1.2.1. Portables

Weight greater than 4.0 kg (9 lbs). Features like a PC, but in a smaller box and with LCD display. Examples: lunchbox or ruggedized laptops (e.g. BSI Computer ).

1.2.2. Laptops/Notebooks

Weight between 1.7 and 4.0 kg (4 to 9 lbs). Features custom hardware and usually a special CPU. Examples: HP OmniBook 3100, COMPAQ Armada 1592DT. The terms laptop and notebook seem equivalent to me.

1.2.3. Sub-Notebooks/Mini-Notebooks

Weight between 1.3 and 1.7 kg (3 to 4 lbs). Features: external floppy drive, external CD drive. Examples: HP OmniBook 800CT, Toshiba Libretto 100, COMPAQ Aero, SONY VAIO 505.

1.2.4. Palmtops

Weight between 0.7 and 1.3 kg (1.5 to 3 lbs). Features: proprietary commercial operating systems. Examples: HP200LX.

1.2.5. Personal Digital Assistants (PDAs)/Handheld PCs (HPCs)

Weight below 0.7 kg (1.5 lbs). Features: proprietary commercial operating systems and often non-Intel CPU with commercial operating systems like PalmOS, EPOC32, GEOS, Windows CE. Examples: Newton Message Pad, Palm III (former Pilot), Psion Series 3 and 5, CASIO Z-7000.

1.2.6. Wearables

Watches, digital pens, calculators, digital cameras, cellular phones and other wearables.

1.4.1. Weight

Don't underestimate the weight of a laptop. This weight is mainly influenced by:

1. screen size

2. battery type

3. internal components, such as CD drive, floppy drive

4. power supply

5. material used for the case, usually they are either from plastics or from magnesium.

1.4.2. Display

Recent laptops come with active matrix (TFT) displays. Laptops with passive matrix (DSTN) are no longer manufactured. Active matrix displays have better color and contrast, but usually cost more and use more power. Also consider the screen size. Laptops may be purchased with screens up to 17". A bigger screen weighs more, costs more, and is harder to carry, but is good for a portable desktop replacement.

1.4.3. Batteries

The available battery types are Lithium Ion (LiIon), Nickel Metal Hydride ( NiMH) and Nickel Cadmium (NiCd). Though almost all current laptops come with LiIon batteries.

LiIon batteries are the most expensive ones but a lot lighter than NiCd for the same energy content, and have minimal - but present - memory effects. NiMH is better than NiCd, but still rather heavy and does suffer some (although less than NiCd) memory effects.

Unfortunately most laptops come with a proprietary battery size. So they are not interchangeable between different models.

1.4.4. CPU

1.4.5. Number of Spindles

Laptops and notebooks are often described by the number of spindles.

1. one spindle: harddisk. Usually sub-notebooks, often provided with an external optical drive (CD/DVD).

2. two spindles: harddisk, optical drive (CD/DVD).

3. three spindles: harddisk, optical drive (CD/DVD), floppy drive. These laptops are often used as desktop PC replacement.

1.4.6. Cooling

An enormously important issue. Anything based on PPC or Pentium will generate enormous amounts of heat which must be dissipated. Generally, this means either a fan, or a heat sink the size of the case. If it's a fan, the air path shouldn't get blocked, or it will overheat and burn out. This means machines with a fan mounted in the bottom are a big, big mistake: you can't use them on a soft surface.

1.4.7. Keyboard Quality

Though you might use your desktop computer to do longer writings, a good keyboard can save you some head- and fingeraches. Look especially for the location of special keys like: <ESC>, <TAB>, <Pos1>, <End>, <PageDown>, <PageUp> and the cursor keys.

1.4.8. Price

Laptops are quite expensive if you compare them with desktops (though maybe not if compared with LCD, IrDA®, PCMCIA capabilities). So you may decide between a brand or no-name product. Though I would like to encourage you to take a no-name product, there are some caveats. I have experienced that laptops break often, so you are better off, when you have an after-sales warranty, which is usually only offered with brand products. Or you may decide to take a second hand machine. When I tried this, I discovered that the laptop market is changing quite often. A new generation is released approximately every three months (compared by CPU speed, harddisk capacity, screen size etc.). So laptops become old very quick. But this scheme often isn't followed by the prices for second hand laptops. They seem too expensive to me. Anyway if you plan on purchasing a second hand machine, review my recommendations on checking the machine.

1.4.9. Power Supply

If you travel abroad pay attention to the voltage levels which are supported by the power supply. Also the power supply is usually one of the heavier parts of a laptop. Another caveat is the power plug, which often is different from country to country.

1.6.1. Related Documentation

1. Hardware-HOWTO

2. Kernel-HOWTO

3. PCMCIA-HOWTO

4. PCI-HOWTO

5. Plug-and-Play-HOWTO

1.6.2. Check Methods in General

If you can't find the necessary information through the above mentioned sources, you are on your own. Luckily, Linux provides many means to help. For details see the section Part V in Linux on the Road Hardware In Detail below. In general you may use:

1. First of all the kernel itself. Look up what kind of hardware is detected by the kernel. You get this information during boot time or by dmesg or by looking into /var/log/messages. For the very first boot messages check /var/log/boot.

2. If your kernel supports the /proc file system you may get detailed information about PCI devices by cat /proc/pci Please read the kernel documentation pci.txt. You may get further information about unknown PCI devices at the Linux PCI ID Repository, the home of the pci.ids file. From 2.1.82 kernels on you may use the lspci command from the pci-utils package.

3. To retrieve information about Plug-and-Play (PNP) devices use isapnp-tools .

4. Use scsi_info by David Hinds for SCSI devices or scsiinfo.

If you don't want to install a complete Linux you may retrieve this information by using a micro Linux ( see Appendix A Appendix A). The package muLinux provides even a small systest program and TomsRtBt comes with memtest. To use memtest you have to copy it on a floppy dd if=/usr/lib/memtest of=/dev/fd0 and to reboot from this floppy.

If your laptop came with Windows, you may determine a lot of hardware settings from the installation. Boot into DOS or Windows to get the information you need.

Using Windows9x/NT to get hardware settings, basically boot Windows, then Start -> Settings -> Control Panel -> System -> Device Manager and write down everything, or make a hardcopy from the display using the <PRINT> key, plus keep a log of settings, hardware, memory, etc.

Using MS-DOS and Windows3.1x you can use the command msd, which is an akronym for MicroSoft Diagnostics. Or you might try one of the numerous DOS shareware utilities: CHECK-IT, DR.HARD and others.

Sometimes it's difficult to know what manufacturer has built the machine or parts of it actually. The FCC "Federal Communications Commission On-line Equipment Authorization Database may be used, if you are having problems identifying the manufacturer of a laptop or notebook computer (or other electronic device,) this site lets you search the FCC database based on the FCC ID number you can usually find on the equipment if it was marketed in the United States of America."

Many laptops are no more compatible with Windows than Linux. David Hinds, author of the PCMCIA drivers, points out that Toshiba notebooks use a proprietary Toshiba PCMCIA bridge chip that exhibits the same bugs under Windows as under Linux. IBM™ Thinkpads have serious BIOS problems that affect delivery of events to the power management daemon apmd. These bugs also affect MS-Windows, and are listed in IBM™'s documentation as considerations.

Some incompatibilities are temporary, for instance laptops that have Intel's USB chip will probably get full USB support, eventually.

3.2.1. BIOS

When starting a fresh installation you should try with standard BIOS options. If something doesn't work you should try to modify BIOS options. For example a well known trouble maker is the Plug-and-Play - PnP option (which comes with different names). See also the BIOS section in the hardware section below.

3.2.2. Boot Options

There are many boot options, which have effects on the behavior of laptops, e.g. apm=on|off and acpi=on|off: For details see BootPrompt-HOWTO and the Kernel documentation in /usr/src/linux/Documentation/kernel-parameters.txt .

3.2.3. Partitioning

Partitioning can be done in a very sophisticated way. Currently I have only some first thoughts. I assume that with laptops there are still some reasons (e.g. updating the firmware of PCMCIA cards and BIOS) to share Linux and Windows9x/NT. Depending on your needs and the features of your laptop you could create the following partitions:

• BIOS, some current BIOSes use a separate partition, for instance COMPAQ notebooks

• suspend to disk, some laptops support this feature

• swap space Linux

• swap space Windows9x/NT

• Linux base

• Linux /home for personal data (please consider an encrypted partition for security reasons, for details about encryption see the according chapter below)

• common data between Linux and Windows9x/NT

• small (~32MB) boot partition for yaBoot (Linux/PPC boot loader), in HFS MacOS Standard format.

Note this chapter isn't exhausting yet. Please read the appropriate HOWTOs first, e.g. the Partition-HOWTO .

3.3.1. GNU parted

GNU parted allows you to create, destroy, resize and copy partitions. It currently supports ext2 and fat (fat16 and fat32) filesystems, Linux swap partitions, and MS-DOS disklabels, as well as Macintosh and PC98. For NTFS file systems see ntfsresize .

3.3.2. ext2resize

ext2resize is a program capable of resizing (shrinking and growing) ext2 and ext3 filesystems. Checks whether the new size the user gave is feasible (i.e. whether the filesystem isn't too occupied to shrink it), connected to the parted project.

3.3.3. fixdisktable

Something was recently published on the <linux-kernel_at_vger.rutgers.edu> mailing list about a partition recovery program. I have neither used , nor examined, nor read much about it (except for the HTML page.) It may be useful to some of you if you have problems with FIPS , Ranish Partition Manager/Utility or Partition Magic destroying your partition information. You can find information on this partition-fixer named "fixdisktable" at his pages. It is quite a ways down in that page. Or look for it via ftp and locate the latest "fixdisktable" in that FTP directory. (Source and binary dist should be available.)

3.3.4. Caveats

Before repartitioning your hard disk take care about the disk layout. Especially look for hidden disk space or certain partitions used for suspend to disk or hibernation mode. Some laptops come with a partition which contains some BIOS programs (e.g. COMPAQ Armada 1592DT). Search the manual carefully for tools like PHDISK.EXE, Suspend to Disk, Diagnostic TOOLS.

Patrick D. Ashmore has recently released a Linux utility to prepare hibernation partitions for use with laptops and notebooks using Phoenix NoteBIOS. "This utility isn't needed to utilize the APM "Suspend-To-Disk" feature ... if you already have a valid hibernation partition, you should be able to use it from any operating system that can handle APM suspends.

However, if one ever upgrades hard drive, memory, or repartitions their hard drive, they discover that they either have to do without the suspend-to-disk feature or boot to DOS and use the PHDISK.EXE program provided with their laptop or directly from Phoenix Technologies.

Now, Linux users are free from this restriction. lphdisk is a Linux utility that properly prepares these partitions for use. Not only does this eliminate having to boot to DOS, but my utility does not exhibit some of the nastier bugs that its DOS counterpart has."

Please see chapter DOS Tools to Repartition a Hard Disk, too.

3.3.5. Multi Boot

Please see the chapter chapter Chapter 15 Different Environments, for information about booting different operating systems from the same harddisk.

3.4.1. From a Boot Floppy plus CD/DVD-ROM - The Traditional Way

With modern laptops, the traditional Linux installation method (from one boot floppy, one support floppy and a package of CD-ROMs or one DVD) should be no problem, if there is a floppy drive and a CD-ROM drive available. Though with certain laptops you might get trouble, if you can not use the floppy drive and the CD/DVD-ROM drive simultaneously, or if the floppy drive is only available as a PCMCIA device, as with the Toshiba Libretto 100. Some laptops support also booting and therefore installation completely from a CD drive, as reported for the SONY VAIO in the VAIO+Linux-HOWTO . Note: Check the BIOS for the CD boot option and make sure your Linux distribution comes on a bootable CD.

Certain laptops will only boot zImage kernels. bzImage kernels won't work. This is a known problem with the IBM™ Thinkpad 600 and Toshiba Tecra series, for instance. Some distributions provide certain boot floppies for these machines or for machines with limited memory resources, Debian/GNU Linux for instance.

3.4.2. From a CD/DVD-ROM - The Usual Way

Newer laptops are able to boot a Linux distribution from a bootable CD/DVD-ROM. This allows installation without a floppy disk drive. If the CD/DVD drive is only available as a PCMCIA device, as with the SONY VAIO PCG-Z600TEK, see the chapter about installing from PCMCIA devices below.

3.4.3. From a DOS or Windows Partition on the same Machine

This is a short description of how to install from a CD-ROM under DOS without using boot or supplemental floppy diskettes. This is especially useful for notebooks with swappable floppy and CD-ROM components (if both are mutually exclusive) or if they are only available as PCMCIA devices. I have taken this method from Installing Debian GNU/Linux 2.1 For Intel x86 - Chapter 5 Methods for Installing Debian :

1. Get the following files from your nearest Debian FTP mirror and put them into a directory on your DOS partition: resc1440.bin drv1440.bin base2_1.tgz root.bin linux install.bat and loadlin.exe.

2. Boot into DOS (not Windows) without any drivers being loaded. To do this, you have to press <F8> at exactly the right moment during boot.

3. Execute install.bat from the directory where you have put the downloaded files.

4. Reboot the system and install the rest of the distribution, you may now use all the advanced features such as PCMCIA, PPP and others.

This should work for other distributions as well. Maybe you have to do some appropriate changes.

3.4.4. From a Second Machine With a Micro Linux On a Floppy

3.4.5. From a Second (Desktop) Machine With a Hard Disk Adapter

From Adam Sulmicki <adam_AT_cfar.unc.edu> I got this hint: Most but not all harddisks in laptops are removable, but this might be not an easy task. You could just buy one of those cheap 2.5" IDE converters/adapters which allow you to connect this harddisk temporarily to a desktop PC with IDE subsystem, and install Linux as usual using that PC. You may do so using the harddisk as the first IDE drive or besides as the second IDE drive. But then you need to be sure that the bootloader (e.g. lilo) writes to the right partition. Also you have to make sure that you use the same translation style as your laptop is going to use (i.e. LBA vs. LARGE vs. CHS ). You will find additional information in the Hard-Disk-Upgrade-HOWTO. You might copy an existing partition, but it is also possible to achieve a customized installation. Instead of a desktop PC you may use a second laptop, which may offer better features like a CD/DVD, to put the harddisk in.

The most common adapter formats are 2.5" IDE adapters (Parallel ATA - PATA). As far as I know Serial ATA (SATA) harddisks are not available for laptops yet. But they could be attached to Serial ATA interfaces in a desktop PC even without an adapter (at least I guess, but I will verify this as soon as I have SATA equipment available). Some small subnotebooks feature 1.8" harddisks with ZIF connectors. These connectors are ATA compatible, and IDE adaptors for them are available also.

3.4.6. From a PCMCIA Device

Since I don't have a laptop which comes with a PCMCIA floppy drive (for instance Toshiba Libretto 100), I couldn't check this method. Please see the chapter Booting from a PCMCIA Device in the PCMCIA-HOWTO. Also I couldn't check whether booting from a PCMCIA harddisk is possible.

Anyway, when you are able to boot from a floppy and the laptop provides a PCMCIA slot, it should be possible to use different PCMCIA cards to connect to another machine, to an external SCSI device, different external CD and ZIP drives and others. Usually these methods are described in the documentation which is provided with the distribution.

The Sony Vaio (PCG-Z600) comes with an external USB-Floppy and an external CD-ROM (PCMCIA). You can boot from the CD-ROM, but afterwards Linux doesn't recognize the same drive anymore so that you can't install from it. You'll have to add the bootparameter linux ide2=0x180,0x360 (or 0x180,0x386?) at the LILO boot prompt if you want Linux to recognize a PCMCIA CDROM after the kernel has booted.

3.4.7. From a Parallel Port ZIP Drive

I couldn't check this method by myself, because I don't have such a device. Please check the appropriate Install-From-Zip-HOWTO . Also I don't know how much these installation methods are supported by the Linux distributions or the micro Linuxes. I suppose you have to fiddle around a bit to get this working.

From Jeremy Impson <jdimpson_AT_acm.org>: I installed Red Hat 6.1 on a Libretto 50CT. It only has a PCMCIA floppy drive. (Which BTW isn't well supported by the default PCMCIA floppy driver. I needed to download a patch from some Linux on Libretto web site.)

Linux will boot off the PCMCIA floppy drive, however. It just can't go back to the floppy after loading the kernel. My Libretto (the 50CT) only has one PCMCIA slot (later models had two slots, or I could have gotten the enhanced port replicator, which gave it another slot). So I couldn't boot off a floppy and then mount a remote filesystem.

So I downloaded ZipSlack (Slackware designed for running from a ZIP disk) and used another PC to load it onto a ZIP disk. I attached the ZIP drive to the Libretto (via the parallel port on the regular port replicator that comes with it) and booted from the Slackware boot disk in the PCMCIA floppy drive. When booted, I removed the floppy drive and inserted and configured a network PCMCIA card. At this point the kernel is in memory and it is using the filesystem on the ZIP disk.

I partitioned and formatted the Libretto's harddrive and then ftp'd Red Hat 6.1 installation source onto one of the new partitions (the partition that would become /home when everything gets done). This is the key: if you don't have enough disk space to have the installation files plus enough to actually install the OS on to, this method won't work.

I shut down the ZipSlack kernel and rebooted it using a RedHat install disk in the floppy drive. I pointed it at the RH6.1 installation media already on the harddrive and started the install.

3.4.8. From a Parallel Port CD Drive (MicroSolutions BackPack)

I had tried myself to install Linux using the MicroSolutions BackPack parallel CD-ROM drive. It is fully supported by Linux and I haven't had any major problem running it. Until version 2.0.36 it is supported by its own module (bpck) while in later versions it has been merged in the more general parallel port ide adaptors (the paride module that relays then of course on more specific low level drivers, which in the BackPack case is still called bpck).

In RedHat 5.x based installations the bpck module is available already at installation stage so you'll just have to select the BackPack cdrom from the Other CD-ROMs at the installation stage and then give it some more options (but autoprobe should work just fine).

In RedHat 6.x (which uses 2.2.x kernels and should then use paride), the BackPack support was dropped. So to install the distribution from such a device, you will have to customize the bootdisk (adding the necessary modules) and the installation will be done without any problem.

Federico Pellegrin has customized a RedHat bootdisk that includes all the parallel CDROM devices that are supported by the distribution Linux kernel version (2.2.12) that should then work on all the supported parallel CDROM devices (even if he only tested it on his MicroSolutions BackPack since he doesn't have other similar hardware). You can find some information on it and the bootdisk image.

As from RedHat 6.2 a supplementary driver disk was included in the distribution to support the paride devices. You'll just have to create the driver disk (the image file is paride.img and can be found in the images/drivers directory) in the usual way and insert it when the installer will ask for it.

Of course I suppose there isn't any problem in installing any other Linux distribution using such a device as long as you can add and configure the appropriate modules at the very beginning of the installation stage, but I haven't tested any.

You should take care of the mode the parallel port uses (ECP, EPP, Output only, PS/2) since some of them may cause your laptop to suddenly freeze or cause serious data corruption. On the other side some modes make the communication dramatically slow (I found the best choice on my laptop the PS/2, but you should make some tests).

This chapter is a courtesy of Federico Pellegrin. Please check also the CDROM-HOWTO.

3.4.9. From a Parallel Port Using a Second Machine

I got this courtesy by Nathan Myers <ncm_AT_cantrip.org>: "Many distributions support installing via a network, using FTP, HTTP, or NFS. It is increasingly common for laptops to have only a single PCMCIA slot, already occupied by the boot floppy drive. Usually the boot floppy image has drivers for neither the floppy drive itself, nor the PCMCIA subsystem. Thus, the only network interface available may be the parallel port.

Installation via the parallel port using the PLIP protocol has been demonstrated on, at least, Red Hat. All you need is a Laplink parallel cable, cheap at any computer store. See the PLIP-HOWTO for details on setting up the connection. Note that (uniquely) the RedHat installation requires that the other end of the PLIP connection be configured to use ARP (apparently because RedHat uses the DOS driver in their installer). On the host, either export your CD file system on NFS, or mount it where the ftp or web daemon can find it, as needed for the installation."

The PLIP Install HOWTO by Gilles Lamiral describes how to install a Linux distribution on a computer without ethernet card, nor CD drive, but just a local floppy drive and a remote NFS server attached by a nullmodem parallel cable.

3.4.10. From a USB Storage Device (Stick, CD, DVD, Floppy)

If booting from an USB device is supported from the BIOS, it is possible to install Linux from this drive. Besides some old laptops, almost all laptops equipped with USB ports support this feature.

First you have to configure the BIOS to boot from an USB device. Sometimes it is possible to use a certain key combination (e.g. <ESC>) during the boot process to select the boot device.

Second you have to install Linux on the boot medium (let's say an USB-Stick) and make it bootable. There are some special Linux distributions available, which are dedicated for such purposes, e.g.:

Feather Linux is a Linux distribution which runs completely off a CD or a USB pendrive and takes up under 64Mb of space. It is a Knoppix remastered (based on Debian/GNU Linux), and tries to include software which most people would use every day on their desktop. See these instructions about installing Feather Linux on an USB drive.

Partboot is dedictated to USB floppy drives and tailored for Linux laptop and notebook installations (you may find tools to resize your partitions as well as PCMCIA support and more).

Damn Small Linux (DSL) is a business-card size (50MB) Live CD Linux distribution. Despite its minuscule size it strives to have a functional and easy to use desktop.

Puppy Linux installs anywhere flash drive, live-CD, zip disk, hard drive, network emulator. All of the applications are in an approx 50-70MB distribution. So, it all runs in a ramdisk, and it all installs in a 128M usb flash card with over half left over for your data.

3.4.11. Installing via Network Interface

On most modern laptops and notebooks with integrated network card, a network installation via the PXE protocol is easy to achieve. This comes in handy especially if there is no CD or DVD drive available.

3.4.12. Installing via VNC

You might ask why do a laptop installation via the VNC protocol? Indeed I know only of one reason to do so. Imagine you want to use a laptop with a broken keyboard you may use the keyboard of the remote machine to achieve the installation. Though you have to do a few key stroke to initiate the VNC installation! You have to prepare the source machine accordingly (instructions how to do so will follow later). For recent SuSE versions the distribution is already prepared, see the handbook for details.

3.4.13. Installing Linux on Small Machines

If you have less than 8MB memory and want to install via NFS you may get the message "fork: out of memory". To handle this problem, use fdisk to make a swap partition (fdisk should be on the install floppy or take one of the mini Linuxes described above). Then try to boot from the install floppy again. Before configuring the NFS connection change to another console (for instance by pressing <ALT><F2>) and issue swapon /dev/xxx (xxx = swap partition ). Thanks to Thomas Schmaltz.

Bruce Richardson has written the 4MB-Laptop-HOWTO on installing a modern Linux distribution (specifically Slackware 7.0) onto laptops with 4MB RAM and <= 200MB hard disks. Another HOWTO is Getting Linux into Small Machines - HOWTO by L.C. Benschop.

3.4.14. Installing Linux on Apple Macintosh PowerBooks and iBooks

Macintosh PowerBooks these days come with a CD/DVD drive but not a floppy drive, but the Linux distributions for PPC support booting and installation off of a CD without any need for a floppy.

Sometimes, when you boot the installer on the PowerBooks, the screen is black; this is easily fixed by tapping the brightness key on the keyboard (somehow, the screen brightness gets reset to zero).

If you have a very recent PowerBook, it may not be supported by the kernel on the installation CD. You can get around this by booting off of a recent kernel downloaded onto your hard drive and using a ramdisk on the CD or hard drive, while still loading the installation packages from the CD (the default). (See the instructions available online for yaBoot or BootX, the Linux/PPC boot loaders; yaBoot is currently better-supported on the newest machines.)

They can also boot/install from the Macintosh (HFS) partition on the internal hard disk.

This part is a courtesy of Steven G. Johnson.

For Linux installation reports see Linux Laptop and Notebook Survey: Apple.

3.4.15. Mass Installation

3.5.1. Display Problems (Missing Lines, Thick Borders)

A common problem during Linux installation (or afterwards) on laptops are missing lines at the bottom of the text console display, so the last command lines or the login prompt are not shown on the screen. Depending on the problem it might help:

• Either using FrameBuffer, e.g. using a Kernel with framebuffer support and a boot option like vga=791, for details see the FrameBuffer-HOWTO.

• Or disabling FrameBuffer, e.g. using a boot option like vga=normal or another resolution Also, you could try passing video=vga16:off on the installer boot prompt.

• As a workaround often it is possible to switch to a second console e.g. <ALT>+<F2> , because this effect is often only related to the first console.

• Check if there are VGA and video boot options configured in the bootloader (e.g. grub, lilo). Try to disable them at least partly, look for options like ywrap, etc.

• Check the BIOS for display settings, often (older) Toshiba laptops behave like this.

• Issue the command resize to get the correct screen size into the system.

• If none of the above helps, you may try to run a start-up-script, which has to run at the end of the boot process. The script has to contain the clear command and/or the reset.

5.1.1. Resources

1. COMPAQ/Digital is the manufacturer of the Itsy.

6.1.1. Resources

1. The manufacturer of the first dedicated Linux PDA the Agenda VR3 is AgendaComputing (out-of-business).

6.2.1. Resources

1. Samsung is the manufacturer of the Yopy.

2. The German Linux-Magazin about the YOPY.

6.3.1. The SHARP System

You may find the official site for information about Linux on the Zaurus at SHARP Japan (in Japanese). You can get the official kernel, either complete or just the patches for the Zaurus there. You can also get the official root-filesystem, that is the initrd, but without the QTopia environment. Check the documentation at SHARP how to create your zImage, bootflag and initrd for flashing the ROM of the Zaurus with your custom setup. Or go to your country-specific division of SHARP to get a complete ROM in one file called "ospack", which is Zaurus.DE for Germany or MyZaurus for the US versions. The kernel is rather old: 2.4.6 with 2.4.6-rmk2-patches and some more from Lineo. The rmk-patches are from Linux ARM Community. The root filesystem from SHARP is known for its weird structure with symbolic links all over the place. The custom compile worked. Remember to hit the "/"-key when the Zaurus displays "Wait... ", so you can choose to start a login instead of QTopia, which is not available then. Unless you downloaded QTopia, (cross-)compiled it and installed it into the root filesystem. BTW, you can create a new user with "adduser", a command provided by BusyBox. BusyBox , provides nearly all UNIX-commands available on the official system.

6.3.2. The Community Systems

Currently I know of two running systems: OpenZaurus and Debian (unofficial).

6.3.3. Synchronization with your Linux PC

The QTopia-Desktop is available as a download from Trolltech for free (as in beer): There is a FAQ, which explains the necessary steps for setup (Ethernet-over-USB). It is not quite up-to-date, because SHARP has tightened the security with their current ROM-release, so you have to give the IP-address 192.168.129.1 to your usb0 network device. You have to download and compile a patch for your kernel to use the driver usbdnet (see aforementioned website). Afterwards, a connection between the QTopia-Desktop and the Zaurus is possible. I had a lot of problems with the usb network layer on my system and could not sync properly. A switch from the driver uhci to usb-uhci for my host dit it. Just recently I had to reboot my notebook and the Zaurus due to a hiccup in the corresponding usb-net drivers. The network via an ethernet-card in the CF-slot is much more reliable than the connection via usb and you can still use the keyboard. The disadvantage is, that you cannot have a storage device in your CF-slot while you are on-line.

6.3.4. External Serial Keyboard

So far I was not able to get it going. There is a site which offers a serial keyboard driver and a patch for the iPAQ . Since the iPAQ and the Zaurus are based on the same CPU architecture, StrongArm, I hope that the driver provided there will also work on the Zaurus. You also need a user-space tool called inputattach, which you can also get from there (source or binary for ARM). I got a Happy Hacking Keyboard Lite with a PS/2 connector. An adaptor translates to serial which itself is plugged into to the Collie serial <-> serial connector. I do not know if this chain is even possible to work. The provided patch applied with only one failing hunk which made a trivial change in the sources (include/linux/serio.h) necessary; check the output. After having re-configured the SHARP kernel config and having compiled the modules, I transferred them to the Zaurus. The modules marked and created are: newtonkbd.o, serio.o, serport.o and perhaps stowaway.o from drivers/char/joystick/ and input.o and keybdev.o from drivers/input/. When you start inputattach, you have to use the line inputattach --newtonkbd /dev/ttyS0, _not_ ttySA0 as stated on the website. For some strange reason, the Collie serial driver does not comply to the official StrongARM documentation of the kernel, which states that the serial ports are accessible via /dev/ttySAx. And because the serial_collie.o is already compiled into the Sharp kernel, you do not have to load the generic module serial.o. Well, I also tried the serial_collie.o as a module, while it was still compiled into the kernel. There were no complaints when loading it, but the system froze unpredictably, so I had to do a soft-reset quite often. Why can I load a module whose code is already in the kernel, I wonder... Anyway, it does not work. :( I tried inputattach in the --dump mode (you have to undefine a variable in the source and recompile) and it seems that there is nothing happening between the serial port and the keyboard. The call for select (man 2 select) fails due to a timeout.

6.3.5. Cross-Compiling

6.3.6. Caveats

SHARP introduced a proprietary serial interface at the bottom of the Zaurus SL-5x00 series. You can buy an adaptor to a regular serial interface from them, but unfortunately, the plug is very thick and you cannot open the slide for the keyboard anymore. Hopefully, you can still plug an external keyboard into this port! You can at least plug the power cord into the adaptor so you do not have to run on battery. There are third-party adaptors available, which overcome this caveat.

There is no speaker for the soundchip of the SL-5500. You have to use the socket for the headphones to hear OggVorbis and the alikes. The buzzer currently supports only 14 different sounds defined in <kernel-source>/include/asm-arm/sharp_char.h , check for SHARP_BUZ_ALL_SOUNDS.

6.3.7. Resources

6.3.8. Conversion from Palm Pilot to Zaurus

See my survey of applications and conversion tools between a conventional PDA operating system (only PalmOS yet, WinCE/Pocket PC and Epoc will follow hopefully) and a Linux PDA.

7.1.1. Resources

1. The manufacturer of the HELIO is VTech .

2. vhl-tools (dead link) , a SourceForge project, works on utilities, patches, documentation and integration of Open Source software for Linux on the VTech Helio PDA.

3. PocketLinux has a port under the GPL, as well as Debian and Redhat packages. But the URL http://www.pocketlinux.com/ seems no longer available.

4. KernelConcepts

5. VR Org cross compiler

6. Linux-Magazin

7.2.1. Resources

1. The manufacturer of the iPAQ PDAs is COMPAQ/HP.

7.2.2. Braille Terminal

Stephane Doyon wrote to the iPAQ mailing list: "We (Nicolas Pitre and myself) have successfully ported BRLTTY to the iPaq and tested the setup by interfacing with a BrailleLite 18 through the serial port. BRLTTY is a program that allows access to the Linux text-mode console using various brands of Braille displays. The BrailleLite is a small electronic Braille notetaker device which can act as a small refreshable Braille display. It also has keys so I can not only read but also type. So there's just the iPaq and the BrailleLite device (with a horrible cable in between) and that's all I need to fully use the console on the iPaq (in text-mode). A pretty powerful setup, yet very small. At the Ottawa Linux Symposium in July, using a network card in my iPaq and borrowing the internet connection they supplied, I was actually able to logon to the net and go read my E-mail, using ssh, pine and lynx! It should be possible to duplicate this setup with other Braille display models or other PDAs."

7.3.1. Resources

1. Apple is the manufacturer of the Newton Message Pad.

2. Newton and Linux Mini-HOWTO .

7.4.1. Resources

1. 3COM is the manufacturer of the PALM-Pilot.

2. PalmOS-HOWTO (former Pilot-HOWTO) by David H. Silber.

3. PilotLink and XCoPilot PilotLink is an utility that performs data transfers from 3com PalmPilot handheld computers to your Linux machine. XCoPilot is an emulator of the PalmPilot operating system that runs under Linux.

4. ucLinux

5. PalmVNC is an implementation of the Virtual Network Client architecture that will allow you to use a Linux or other UNIX machine to put up a (tiny) X Window on a 3COM PalmPilot.

6. Survey of Linux and BSD Applications for the Palm

7.5.1. USB

From /usr/src/linux/Documentation/usb/usb-serial.txt:

HandSpring Visor USB docking station. There is a webpage and mailing lists.

Handspring VISOR Platinum serial port is tunneld through USB, so load usbserial.o with modul parameters vendor=0x82d product=0x100 (usbmgr.conf) USB is made active by starting the HotSync synchronisation per: pilot-xfer /dev/ttyUSB0 -b -/visor/

7.6.1. Resources

1. Psion-HOWTO.

2. PLPtools is a set of libraries and utilities for enabling Unix (mainly Linux) systems to communicate with a Psion palmtop over a serial line. On Linux, a connection over IrDA, using the IrCOMM feature is also possible. A shared library encapsulates the highlevel protocol (PsionLinkProtocol) and thus makes it easy to write applications without extensive knowledge of the protocol itself. A daemon (ncpd) handles the serial connection and provides it's services on a local TCP socket.

3. The OpenPsion (formerly PsiLinux/Linux7k) is a project to port the unix-like operating system Linux to a small group of palmtops.

9.2.1. Touchscreen

The XFree86-Touch-Screen-HOWTO describes how to setup X11 for touchscreens. There is also a short survey of Linux laptops, which feature a touchscreen and/or have a pen as an input device and a survey about Linux on Tablet PCs.

9.2.2. Screen Rotation

9.4.1. Soft Keyboard / On Screen Keyboard

9.4.2. Remote Keyboard

Some Tablet PCs are equipped with a remote keyboard. Data between keyboard and Tablet PC may be interchanged via InfraRed, BlueTooth or other means. If these solutions are hardware based only, they should work easily with Linux. Otherwise you probably need the technical specifications from the manufacturer.

9.4.3. Virtual Keyboard

There are different approaches for virtual (non physical) keyboards. Whether they work with Linux or not I could not verify yet.

• Viki made by VKB

• Keyboard Perception Chipset made by Canesta

• SenseBoard

• LightGlove

• Scurry made by SAIT

• Kitty

10.1.1. Connectivity to Mobile (Cellular) Phones with non-Linux Operating System

For NOKIA cellular phones see GNOKII project. And Linux Nserver. This project aims to produce a GPL replacement for Nokia's Windows Nserver, and maybe improve upon it along the way. Initially it will emulate the Windows 3.1 version (ie. allow backup, restore and install).

openWAP is an open source project for the implementation of the Wireless Application Protocol (WAP) for use with browsers, servers and tools. WAP is used by PDA devices, cell phones, pagers and other wireless devices to transmit internet content to these devices. The project is still in its early stages and nothing can be downloaded yet.

GSMLIB is a library to access GSM mobile phones through GSM modems. Features include: modification of phonebooks stored in the mobile phone or on the SIM card, reading and writing of SMS messages stored in the mobile phone, sending and reception of SMS messages. Additionally, some simple command line programs are provided to use these features.

Kannel is an open source WAP gateway. It attempts to provide this essential part of the WAP infrastructure freely to everyone so that the market potential for WAP services, both from wireless operators and specialized service providers, will be realized as efficiently as possible.

Kannel also works as an SMS gateway for GSM networks. Almost all GSM phones can send and receive SMS messages, so this is a way to serve many more clients than just those using a new WAP phone.

10.1.2. Mobile (Cellular) Phones with a Linux Operating System

There are some mobile phones with Linux operating system available. As well as Linux distributions for mobile (cell) phones.

11.1.1. Related Documentation

1. Kodak-Digital-Camera-HOWTO by David Burley <khemicals_AT_marblehorse.org> .

11.1.2. Introduction

For information about cellular phones and digital cameras see the Infrared Devices and Linux Survey and my InfraRed-HOWTO .

Newsgroup: rec.photo.digital .

The Flashpath adapter is a diskette like device which is used to transfer data from a digital camera to a computer. See Flashpath for Linux and James Radley's flashpath homepage . Note: it is not officially certified and released under GPL.

12.2.1. SMBios

Desktop Management Interface (DMI) Standards generate a standard framework for managing and tracking components in a desktop pc, notebook or server. DMI was the first desktop management standard. The DMI Home Page is a repository of all DMI-related information from the specification to tools to support to the Product Registry of DMI-certified products.

Dmidecode reports information about your system's hardware as described in your system BIOS according to the SMBIOS/DMI standard (see a sample output). This information typically includes system manufacturer, model name, serial number, BIOS version, asset tag as well as a lot of other details of varying level of interest and reliability depending on the manufacturer. This will often include usage status for the CPU sockets, expansion slots (e.g. AGP, PCI, ISA) and memory module slots, and the list of I/O ports (e.g. serial, parallel, USB).

There is also an alternative implementation of a DMI table decoder. Libsmbios is a cross-platform library intended to be used to obtain common information available in a BIOS using a unified API. Currently, it can programmatically access any information in the SMBIOS tables. It also has the ability to obtain Dell system-specific information such as the Dell System ID number, service tag, and asset tag. Future plans include APIs for $PIR and mptable mapping. There is a C API for some of the more commonly used functions, and example binaries to show off most of the facilities.

12.3.1. SpeedStep

Speedstep is a feature of recent CPUs made by Intel, which lets you set CPU frequency. There are different Linux tools to get this to work. Similar features are also available for other CPUs from AMD or the StrongARM CPU, I will describe this in a later issue (assistance welcome).

Before configuring SpeedStep have a look into the BIOS options.

12.4.1. CPU: Pentium-M

Robert Freund has written a concise HOWTO about controlling ACPI Centrino(TM) features via software in Linux. He describes how to control CPU frequency and other energy saving modes, as well as how to get information about the battery state.

12.4.2. Chipset: 855/915

The Intel 855/915 chipset families are designed to deliver better performance at lower power. The chipsets are available as discrete memory controller hub (e.g. Intel 855PM). Or as an integrated graphics and memory controller hub (e.g. Intel 855GM). Intel provides the Extreme Graphics driver for Linux, which includes AGP GART and DRM kernel modules as a binary files. I have no experience with this drivers, because the chipsets work with XFree86/X.org drivers, too. The Pentium-M CPU may come accompanied with other graphics chipsets too, e.g. from ATI, nVIDIA or Trident.

12.4.3. Wireless LAN: PRO/wireless 2100/2200 LAN Mini-PCI Adapter

There are different solutions to get these cards running with Linux: drivers from Intel, NDIS wrapper and Linuxant driverloader (commercial).

ipw2100, Intel's Open Source driver with included firmware, for the first Centrino generation (incl. WEP and WPA together with HostAP). For the second generation of Intel's miniPCI modules: PRO/Wireless 2200BG (802.11g/802.11i), the ipw2200 project provides a driver. Third generation PRO/Wireless 2915ABG (IEEE 802.11b, 802.11g und 802.11a) miniPCI cards will be supported by the ipw2200 project, too.

Intel didn't provide drivers, when the begun to sell their Centrino technology. During this time there have been other solutions: Some vendors refuse to release technical specifications or even a binary Linux driver for their WLAN cards. NDIS wrapper tries to solve this by making a kernel module that can load NDIS (Microsoft-Windows Network Driver Interface Specification) drivers. Currently there are two implementations available. The commercial Linuxant Driverloader supports a broad range of chipsets including Intel's PRO/Wireless 2100 LAN Mini-PCI Adapter. There is also ndiswrapper an Open Source solution by Pontus Fuchs.

As another workaround was the usage of a Linux-supported miniPCI WLAN card. These cards are difficult to get, but some desktop WLAN PCI cards contain miniPCI cards. Often it is a tedious task to build them into a laptop. Kernel maintainer Theodore Tytso has written a manual about achieving this task. You may also use a wireless PCMCIA or CF card instead. This solution may provide more flexibility, because you may use a PCMCIA or CF card in different devices and choose the Linux driver of your choice. You may also extend the wireless range by adding antennas to some cards. For Linux compatibility there is the TuxMobil PCMCIA/CF Card Survey. In the future, manufacturers will probably offer alternative miniPCI solutions. DELL is already doing so for their Latitude D series.

12.4.4. Conclusion

Though Linux support is not yet complete, some features of the Centrino(TM) technology already make it worthwhile to take into account when buying your next laptop. Though the new CPUs are named so similarly to existing ones that some people mix them up, they are completely different inside. Compared to the Pentium-4 Mobile CPU, the Pentium-M will allow a smaller form factor for laptops, making them more portable and lighter. Because of their higher clockspeed, the Pentium-4 CPUs have produced too much heat to build them into slimline notebook cases. Therefore, very flat notebooks have only been available from Apple or with a Pentium III Mobile CPU. Also, the battery power the Pentium-M consumes for a given level of performance will decrease, but I do not have a benchmark about how much the savings actually are yet. PENN Computing offers a nice comparison of Pentium-M and Pentium-4 Mobile. Note: The character M in Pentium-M suggests "mobile". Therefore some people mix this kind of CPU with the mobile versions of the Pentium-III/Pentium-4 CPU.

Laptops based on the Centrino(TM) features are already very popular in the Linux community. Installation reports for almost all Centrino based laptops available at TuxMobil.

12.5.1. Linux Compatibility Check

With the probe command, which is included in the PCMCIA-CS package by David Hinds you can get the type of the PCMCIA controller. Also available by the command cat /proc/pci.

12.5.2. Related Documentation

1. PCMCIA-HOWTO

12.5.3. PCMCIA Configuration - Survey

In the mailing lists where I'm a member, the question "How can I set up PCMCIA support, after the Linux installation?" comes up sometimes. Therefore I try to give a short survey. But the authoritative source for the latest information about the PCMCIA Card Services for Linux, including documentation, files, and generic PCMCIA information is the Linux PCMCIA Information Page . For problems with PCMCIA and APM see the chapter APM.

12.6.1. Linux Compatibility Check

12.6.2. Related Documentation

1. First of all the XFree86 documentation itself. Often locally available at /usr/share/doc/xfree86*. Or the X.Org documentation.

2. XFree86-HOWTO

3. XFree86-Video-Timings-HOWTO

4. XFree86-XInside-HOWTO

5. X-Big-Cursor-mini-HOWTO (useful when running X11 on a notebook with low contrast LCD)

6. Keyboard-and-Console-HOWTO

7. Framebuffer-HOWTO

12.6.3. Survey X11-Servers

You might discover that some features of your laptop are not supported by XFree86 or X.Org. , e.g. high resolutions, accelerated X or an external monitor. Therefore I give a survey of available X11 servers.

1. XFree86

2. X.Org.

3. VESA Frame-Buffer-Device, available with 2.2.x kernels and XFree86 3.3.2 or greater. See FBDev.ORG and FB FAQ and kernel source /usr/src/linux/Documentation .

   Please check the latest release of DirectFB for a dedicated Framebuffer Driver for the NeoMagic chip and other chipsets, with support for acceleration. DirectFB is a thin library that provides developers with hardware graphics acceleration, input device handling and abstraction, an integrated windowing system with support for translucent windows and multiple display layers on top of the Linux framebuffer device. It is a complete hardware abstraction layer with software fallbacks for every graphics operation that is not supported by the underlying hardware.

4. Xi Graphics , commercial, also known under their former names AcceleratedX or Xinside.

5. SciTech, commercial.

6. Metro-X, commercial.

If you can't get an appropriate X11 server working, but cannot afford a commercial X11 server you may try the VGA16 or the mono server included in XFree86.

12.6.4. Resources

You may find a survey about current graphics chips used in laptops and notebooks at TuxMobil.

12.6.5. External Monitors: LCD, CRT, TV, Projector

There are several different methods to activate support for an external monitor: as a BIOS option or during runtime with a keystroke e.g. <Fn>+<F4>.

Read the X11 docs about your graphics chip carefully, for instance for the NeoMagic NM20xx chips you have to edit /etc/XF86Config by configuring intern_disp and extern_disp. Note: As far as I know these options are only valid for XFree86 3.3.x, for XFree86 4.x I couldn't find a similar option.

If you can't get the external monitor to work with XFree86, try a demo version of the commercial X11 servers mentioned above. Also check with the RedHat and SuSE WWW sites as they may have new, binary-only, X11 servers that may work with your laptop. Or check X11 servers from X.Org.

12.6.6. Power Management for Graphics Cards

The uptime on batteries can be improved by enabling the power management features of the graphics card. There are tools available to change the clock frequency and to shut down the backlight of the display. Usually these tools are specific for a graphics card or a graphics card manufacturer. Here are some techniques for graphics cards made by ATI.

The proprietary fglrx driver from ATI needs to be enabled by adding the PowerState option to the Device Section in the /etc/X11/xorg.conf X11 configuration file:

Section "Device" Identifier "aticonfig-Device[0]" Driver "fglrx" Option "PowerState" "1" EndSection

After rebooting or re-starting X11 you can start the power save mode with the command aticonfig --set-powerstate=1 --effective=now. Use aticonfig --list-powerstates to get all available powerstates.

For ATI Radeon graphics cards the rovclock tool can be used to save power e.g. rovclock -c 80 -m 80 to use only 80MHz chip and memory frequency. The command radeontool light off switches the backlight off, if closing the lid or using an extra key is not an option.

The ACPI backlight driver by Holger Macht in 2.6.x for IBM, Toshiba, ASUS laptops adds support for the generic backlight interface below /sys/class/backlight. The patch keeps the procfs brightness handling for backward compatibility. For this to archive, the patch adds two generic functions brightness_get and brightness_set to be used both by the procfs related and the sysfs related methods.

12.6.7. Miscellaneous

Sometimes you may encounter a display not working properly in text mode. Currently I don't have any recommendations, please see Keyboard-and-Console-HOWTO .

Take care of the backlight as far as I know this device can only bear a limited number of uptime circles. So avoid using screensavers too much.

For problems with X Windows and APM please see the APM chapter.

vbetool uses LRMI in order to run code from the video BIOS. Currently, it is able to alter DPMS states, save/restore video card state, and attempt to initialize the video card from scratch. It exists primarily in order to increase the chances of successfully recovering video state after an ACPI S3 suspend-to-RAM.

12.9.1. Laptop Displays

12.9.2. PDA Displays

pxl2000 is a free ISO 8859-15 (i.e. ISO 8859-1 with Euro symbol) encoded monowidth dot matrix typeface for the X Window system (X11). It is currently available in nine sizes: 4x8, 5x10, 6x12, 7x14, 8x16, 9x18, 10x20, 11x22 and 12x24 pixels. It's design objectives are:

• Readability; fitness to be used as a default screen font, especially on reverse-color X11 terminals

• Optimization for program code through visually distinct characters L, l, 1, 7, |, I, i and 0, O and more.

• Complete ISO 8859-15 character set.

• Many point sizes to ensure optical consistency across different computers with different screen resolutions (encompassing anything from PDA displays to 20" screens).

• Fitness for displaying ASCII art and codework/code poetry, from viewing graphics in aview, watching TV in ttv and DVDs in mplayer with -vo aa to reading mailinglists like _arc.hive_, 7-11 and writing in mutt.

• Clean, minimalist visual design; no serifs, a square minuscule base matrix, rounded edges. This is a computer terminal font; it should not look like a low-res imitation of print type.

The author Florian Cramer employs this font in his "anti-desktop" setup consisting of the ratpoison window manager and GNU screen inside an rxvt terminal (with reverse color and no scrollbars), similar to what is described in this FreshMeat article .

12.10.1. Linux Compatibility Check

The only way I know to check this, is to compile the different sound drivers into the kernel and check whether they are detected or not. The best way to do so, is to compile them as modules because it's easier to load different parameters such as interrupts and IO ports this way. For the 2.2.x kernels, read /usr/src/linux/Documentation/sound/Introduction by Wade Hampton. This document may help you get started with sound. Also, you might try one of the commercial sound drivers mentionend below. To check whether sound works or not you may try e.g. xmms and one of the sounds provided in /usr/share/sounds.

12.10.2. Related Documentation

1. Sound-HOWTO

2. Visual-Bell-mini-HOWTO

3. You may find also some good sound HOWTOs at the Linux Audio Users Guide - LAU

12.10.3. Survey Sound Drivers

1. ALSA Advanced Linux Sound Architecture . The Advanced Linux Sound Architecture aims to: be a fully-modularized sound driver which supports kerneld/kmod, ensure compatibility with most binary OSS/Lite applications, create an ALSA Library (C,C++) which covers the ALSA Kernel API for applications, and create ALSA Manager, an interactive configuration program for the driver. With Kernel 2.6 these modules will be part of the Linux Kernel.

2. UNIX Sound System Lite / OSS provides commercial sound card drivers for most popular sound cards under Linux. These drivers support digital audio, MIDI, Synthesizers and mixers found on sound cards. These sound drivers comply with the Open Sound System API specification. OSS provides a user-friendly GUI which makes the installation of sound drivers and configuration of sound cards very simple. OSS supports over 200 brand name sound cards. OSS drivers provide automatic sound card detection, Plug-n-Play support, support for PCI audio soundcards and support.

3. As a last resort you may try the speaker module pcsnd, which tries to emulate a soundcard.

12.10.4. Additional Soundcards

VXPocket looks like a finally medium2high-end soundcard solution for onboardwise badly equipped laptops. Note: I didn't check whether this is a PCMCIA card or not. PCMCIA sound cards are probably not supported.

Also USB may be an alternative. Most USB audio devices are supported by recent kernels. An example is Labtec Axis 712 Stereo Headset (headphones and microphone) which works in full-duplex mode. For more info about this and other Linux-compatible USB audio devices see the USB Survey and my Mobile USB Linux Hardware Survey .

12.10.5. External and Internal CD Drives

For playing CDs/DVDs from an external or internal CD/DVD drive, see chapter Section 12.32 CD/DVD Drive below.

12.11.1. Linux Compatibility Check

Usually there are no problems with Linux and the keyboard. Though there are two minor caveats: First the setleds program might not work. Second the key mapping might not fit your needs. Some UNIX users and vi users expect to find the <CONTROL> key to the left of the <A> key. Many PC-type keyboards have the <CAPS-LOCK> key there. You may use xmodmap or loadkeys to re-map the keyboard. Some laptops (e.g., Toshiba) allow you to swap the <CAPS-LOCK> and <CONTROL> keys. Mark Alexander offered this solution in the linux-laptop mailing list: On RedHat, it's a one-line patch to /usr/lib/kbd/keytables/us.map , or whatever file is referenced in /etc/sysconfig/keyboard:

*** us.map~ Tue Oct 31 14:00:07 1995 --- us.map Thu Aug 28 13:36:03 1997 *** 113,119 **** keycode 57 = space space control keycode 57 = nul alt keycode 57 = Meta_space ! keycode 58 = Caps_Lock keycode 59 = F1 F11 Console_13 control keycode 59 = F1 alt keycode 59 = Console_1 --- 113,119 ---- keycode 57 = space space control keycode 57 = nul alt keycode 57 = Meta_space ! keycode 58 = Control keycode 59 = F1 F11 Console_13 control keycode 59 = F1 alt keycode 59 = Console_1

12.11.2. External (Second) Keyboard

A second (or external) keyboard can be attached using the PS/2 port (I suppose this is not possible via the serial port, since there is no keyboard controller for the serial port) or via USB port. Also there is one laptop with a detachable keyboard the Siemens Scenic Mobile 800. This machine uses an infrared connection to the keyboard, but I don't know whether this works with Linux.

---

12.11.2.2. External PS/2 Keyboard

Don't plug the external keyboard in while the laptop is booted, or plug the mouse in the keyboard port and the keyboard in the mouse port. On a Toshiba, this caused one user to have to completely shutdown the laptop, remove the keyboard/mouse, and do a cold reboot.

For PS/2 ports there is a so called Y-Cable available, which makes it possible to use external mouse and external keyboard at the same time if your laptop supports this feature.

Parport to AUX port adapter In some cases one kbd port and one aux port is not enough and you may want to add another keyboard or mouse. You can use this adapter, together with the parkbd module for that.

On some laptops a splitter works to allow both mouse and keyboard to be plugged in; on others it doesn't work at all. If you want to use both, you better check that it works.

12.12.1. Related Documentation

1. Keyboard-and-Console-HOWTO

12.12.2. Utilities

Some laptops offer extra buttons, e.g. - internet, mail keys, or zone keys. If the Linux kernel and XFree86/X.org generate key codes for them, hotkeys or just plain xmodmap (see the man page of this X11 programm for details) may be helpful. If Linux doesn't know about the keys, you'll have to patch the kernel first. Though I'm not quite sure some tools don't seem to require this, I don't understand how it works yet. You may also use xhkeys . This tool allows you to assign an action to any key that is otherwise unused in X (such as the "menu" key on a 105 key keyboard, extra keys on some keyboard models, or odd keys on laptops). The action assigned to a key or key combination (key and modifiers) can be a builtin operation, a call to an external application, the sending of a key event (simulating a key press/release), or the sending of a mouse button event (simulating a button press/release).

To get information about unknown keyboard or mouse events you may use showkey and mev (the last one is from the gpm package) on a console screen. But some of the extra keys are not found with these tools.

keyTouch makes it possible to easily configure the extra function keys of a keyboard (like multimedia keys). It allows the user to define which program will be executed when a key is pressed. By using keyTouch-editor the user can easily create a keyboard file for his or her laptop to get the laptop supported.

akdaemon is a userland daemon to invoke "the fun keys" by accessing a dev node offered by the complementary kernel patch or the funkey programm .

The hotkeys package is supposed to listen for those multimedia keys.

Special ("easy access") buttons are supported by LinEAK . Here is an example lineakd.conf file:

# LinEAK Configuration file for Compaq Easy Access Key 2800 (6 keys) # Global settings KeyboardType = CIKP800 CdromDevice = /dev/cdrom MixerDevice = /dev/mixer # Specific keys of your keyboard internet = xosview search = kfind mail = kmail multimedia = "artsdsp xmms" voldown = "aumix -v -2" volup = "aumix -v +2" # end lineakd.conf

xbindkeys is a program that associates keys or mouse buttons to shell commands under X. After a little configuration, it can start many commands with the keyboard (e.g. control+alt+x starts an xterm) or with the mouse buttons.

ACME is a small GNOME tool to make use of the multimedia buttons present on most laptops and Internet keyboards: Volume, Brightness, Power, Eject, My Home, Search, E-Mail, Sleep, Screensaver, Finance, WWW, Calculator, Record, Close Window, Shade Window, Play, Stop, Pause, Previous, Next, Groups, Media, Refresh, and Help buttons. It works on all the platforms GNOME supports (laptops and PCs). It uses either OSS or ALSA for Volume control.

For some laptop series there are Linux utilities available to control special hotkeys and other features.

• toshutils by Jonathan Buzzard for some Toshiba models.

• Tclkeymon is a daemon for Toshiba laptops that use ACPI and the Toshiba ACPI extensions. It monitors function keys and Toshiba-specific buttons (including the CD player buttons and the state of the laptop lid) and responds appropriately.

• tpctl IBM ThinkPad configuration tools for Linux by Thomas Hood.

• ThinkPad Buttons enables the special keys that are found on the keyboard of an IBM ThinkPad. It is possible to bind a program to each of the buttons. It has an on-screen display (OSD) to show volume, mute, LCD brightness, and some other things.

• IBM ThinkPad Scroll Daemon

• i8k utils for DELL laptops.

• hotkey Linux driver for ACER laptops.

• OSL is a simple pbbuttonsd (used on Apple laptops to access the 'special keys' like volume, eject, etc.) client. It uses the xosd-lib to display the current values which makes it look a lot more like OSX than other pbbuttonsd-clients.

• PBButtons enables hotkeys on Apple iBook/PowerBook/TiBook. I have heard it works well on x86 architectures, too.

• ikeyd is a simple daemon which sets the volume or ejects a CDROM when hotkeys are pressed on an iBook/TiBook.

• jogdiald for the Jog-Dial on SONY laptops offers support for extra keys, too.

• omke is a set of small programs and patches to configure some advanced features of your HP OmniBook (usually things that HP has not documented) such as enabling/disabling the extra onetouch/multimedia keys. This tool works also for some Toshiba notebooks.

12.17.1. Linux Compatibility Check

You may check your mouse with the mev command from the GPM package.

12.17.2. Related Documentation

1. 3-Button-Mouse-HOWTO for serial mice

2. Kernel-HOWTO

12.17.3. Mice Species

1. Trackpad, Touchpad, are used with the majority of current laptops

2. Trackball, e.g. COMPAQ LTE

3. Pop-up-Mouse, e.g. HP OmniBook 800

4. Trackpoint, Mouse-Pin, e.g. IBM™ ThinkPad and Toshiba laptops

5. 3 Button Mice, e.g. IBM™ Thinkpads at least the 600s and some COMPAQ models e.g. Armada M700. I have heard rumor about a 3 button mouse for Texas Instruments Travelmates, but couldn't verify this yet.

6. Touchscreen, e.g. some Fujitsu-Siemens laptops, TabletPCs and PDAs

12.17.4. PS/2 Mice

Most of the mice used in laptops are PS/2 mice (actually I don't know one with another mouse protocol). You may communicate with the PS/2 mouse through /dev/psaux or /dev/psmouse. If you use X Windows this device and the protocol has to be set in /etc/X11/XF86Config. In earlier releases, sometimes the GPM mouse manager and X Windows had trouble sharing a mouse when enabled at the same time. But as far as I know this is no problem anymore for the latest versions.

Speaking of Emulate3Buttons, 100ms is usually better than the 50ms allowed in most default setups of /etc/X11/XF86Config for XFree86 3.x:

Section "Pointer" ... Emulate3Buttons Emulate3Timeout 100 ... EndSection

Or in /etc/X11/XF86Config-4 for XFree86 4.x:

Section "InputDevice" ... Option "Emulate3Timeout" "100" Option "Emulate3Buttons" "true" ... EndSection

12.17.5. Touchpad

Usually a touchpad works with the PS/2 mouse device /dev/psaux and the PS/2 protocol (for GPM and X11, for X11 it seems also worth to check the GlidePointPS/2 protocol).

The Synaptics TouchPad driver has the following functions (some functions require features from the touchpad that must be present, multifinger taps for example):

1. Movement with adjustable, non-linear acceleration and speed (Options: MinSpeed, MaxSpeed, AccelFactor)

2. Button events through short touching of the touchpad (Options: MaxTapTime, MaxTapMove)

3. Double-Button events through double short touching of the touchpad

4. Dragging through short touching and holding down the finger on the touchpad

5. Middle and right button events on the upper and lower corner of the touchpad (Option: Edges)

6. Scrolling (button four and five events) through moving the finger on the right side of the touchpad (Options: Edges, VertScrollDelta)

7. The up/down button sends button four/five events

8. Adjustable finger detection (Option: Finger)

9. Ext Mouse repeater support - Alpha! (Option: Repeater)

10. Multifinger taps: two finger for middle button and three finger for right button events

11. Online configuration through shared-memory (in development) (Option: SHMConfig)

The synclient command is provived with the driver sources (note it's not included in SuSE Linux, at least not until 9.3). The command queries and modifies the Synaptics TouchPad driver parameters on the fly.

Tipping with one, two or three fingers on the touchpad simultaneously results in pressing the left, middle and respectively the right mouse-button.

There is also another touchpad driver available. The Synaptics Touchpad Linux Driver - tpconfig supports pointing devices used in notebooks by Acer, Compaq, Dell, Gateway, Olivetti, Texas Instruments, Winbook, and others.

Dell and Sony have started incorporating a touchpad, touchstick from ALPS. They are in at least the Dell Latitude CPx and the Sony VAIO laptop lines. Maintainer Bruce Kall writes: "tpconfig does NOT support them at this time, but I am in the process of getting the API from ALPS and will be incorporating this in the next version of tpconfig. The Dell's also incorporate the ALPS GlideStick in the middle of the keyboard (like the stick pointer in some of the IBM Thinkpads). I also intend to support the disabling of "tapping" the GlideStick as well. Tapping of the touchpad/touchsticks drives me crazy, I'm not sure about you (causes the "selection" of things on the screen when you don't want to)!"

tpconfig is a command-line utility to set options on Synaptics Touchpad and (now) ALPS Glidepad/ Stickpointers. Most people primarily use it to turn off the "tap mode" on laptop touchpads.

How to use tpconfig: tpconfig is currently supported as a command-line configuration tool. The PS/2 port does not currently support sharing. Therefore the tpconfig utility will not work while any other mouse driver is loaded (e.g. gpm). This also means that you cannot use tpconfig while X Windows is running. The suggested use of tpconfig is to run it from a startup script before gpm is started.

IBM ThinkPad Scroll Daemon

Not all touchpads are being from Synaptics, e.g some Gateways incorporate an EZ-Pad (Registered TM) and there might be other brands. The TPREV.EXE utility will verify you have a Synaptics touchpad.

The recent gpm package (version >=1.8, maybe earlier versions contain touchpad support, too) includes the above mentioned Synaptics touchpad device driver. This device driver has been developed by H. Davies <hdavies_AT_ameritech.net>. Instead of using the PS/2 compatibility mode of touchpad devices, you can now use native touchpad mode with some pretty impressive features.

In addition to translating finger motion into mouse motion and supporting the buttons, this support currently has several features (from the README):

• a "tap" on the TouchPad causes a left mouse click

• a "tap" followed quickly by a finger motion causes a left button drag type action.

• a "tap" in one of the corners causes an action the default configuration is upper right causes middle mouse click and lower right causes right mouse click

• more pressure on the touch pad speeds the motion of the cursor

• a "tap" with a motion component (default > 2mm) initiates a toss and catch sequence. This is terminated by a finger touch on the pad (the toss also ends after 1 sec since that is the idle timeout period for the touchpad).

• if the finger moves close to an edge then the mouse motion will be continued in that direction so that you don't need to pick up your finger and start moving again. This continued motion is pressure sensitive (more pressure is faster motion).

These features can be enabled/disabled and many of them have time and speed parameters which can be adjusted to the taste of the user.

It seems gpm is best known as a console biased tool. This is true, but you may use it as an X11 input device. gpm is used as a repeater device. In this way you can use both the built-in synaptics touchpad with all the features and at the same time a serial mouse (with three buttons). This all works smoothly together. X11 reads the mouse events from a named pipe /dev/gpmdata in a protocol it understands, which in my case is Mouse-Systems-Compatible (5bytes). Most 3-button mice use the default protocol. So a simple reconfiguration in XF86Config is all that is required, after starting gpm in an appropriate way, of course.

gpm could be started on your laptop with the following arguments : /usr/bin/gpm -t synps2 -M -t ms -m /dev/ttyS0 . Both touchpad and serial mouse work in console and X11 mode. You do have to create the named pipe /dev/gpmdata yourself.

Tapping with two fingers simultaneously to simulate a middle mouse button works on Logitech touchpads used in a few machines.

Thanks to Geert Van der Plas for most of the touchpad chapter.

12.17.6. Jog-Dial

The "Jog-Dial" is an input device used in the SONY VAIO laptop series. You may find a Jog-Dial driver by Takaya Kinjo. Probably you have to change two things in the spicdriver/Makefile:

CCFLAG has to be extended with -D_LOOSE_KERNEL_NAMES

CCFLAG has to be extended with -I/usr/src/linux-<kernel-version>/include

The README seems to be in Japanese, here is an English version.

$ tar xvzf jogutils.tar.gz $ cd jogutils $ make $ su # mknod /dev/spic c 60 0 # modprobe spicdriver/spicdriver # exit $ cp jogapp/rcfile ~/.jogapprc $ jogapp/jogapp

ISHIKAWA Mutsumi wrote the jogdiald driver, which runs entirely in user-space (no kernel modules required).

rsjog. is a modification of the sjog utility.

12.17.7. Touchscreens

The only modern laptops I know which include a touchscreen are the Fujitsu Biblo 112/142 (aka MC 30) and the Palmax PD 1000/1100 (aka IPC 1000/1100).

The latest version of the Linux Compaq Concerto Pen Driver is available from Joe Pfeiffer's home page.

A current survey of drivers you may find at my page Touchscreen Laptops and Linux .

12.17.8. Pen Devices, Mousepoints

IBM and Toshiba laptops currently come with a pen devices instead of a mousepad or trackball.

It needs some time to get used to this kind of pointer device. It may help to rest your palm at the front rest. Also it's recommended to reduce the mouse speed.

12.17.9. External Mouse

For better handling, e.g. with a 3 button mouse you may use an external mouse. This is usually a serial mouse or a PS/2 mouse, or in our days a USB mouse, appropriate to the port your laptop offers. Usually this is no problem. The only thing I currently don't know a solution for is the automagic detection of a newly plugged in mouse from X11. To get it work you have to restart your X server.

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12.17.9.1. PS/2 Mouse

For PS/2 ports there are so called Y-Cable available, which make it possible to use external mouse and external keyboard at the same time if your laptop supports this feature.

Don't plug in the external mouse while powered up. If you have separate mouse and keyboard ports, make sure you plug the mouse in the mouse port and the keyboard in the keyboard port. If you don't, you may have to do a hard reboot of the laptop to get it to recover.

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12.17.9.3. USB Mouse

This part is taken from The Linux USB Sub-System by Brad Hards.

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12.17.9.3.1. USB Human Interface Device (HID) Configuration

12.17.9.3.1.1. General HID Configuration

There are two options for using a USB mouse or a USB keyboard - the standalone Boot Protocol way and the full featured HID driver way. The Boot Protocol way is generally inferior, and this document describes the full featured way. The Boot Protocol way may be appropriate for embedded systems and other systems with resource constraints and no real need for the full keyboard and mouse capabilities.

It is important to remember that the HID driver handles those devices (or actually those interfaces on each device) that claim to comply with the Human Interface Device (HID) specification. However the HID specification doesn't say anything about what the HID driver should do with information received from a HID device, or where the information that is sent to a device comes from, since this is obviously dependent on what the device is supposed to be doing, and what the operating system is. Linux (at the operating system kernel level) supports four interfaces to a HID device - keyboard, mouse, joystick and a generic interface, known as the event interface.

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12.17.9.3.1.2. HID Mouse Configuration

In the kernel configuration stage, you need to turn on USB Human Interface Device (HID) support and Mouse Support Do not turn on USB HIDBP Mouse support. Perform the normal kernel rebuild and installation steps. If you are installing as modules, you need to load the input.o, hid.o and mousedev.o modules.

Plug in a USB mouse and check that your mouse has been correctly sensed by the kernel. If you don't have a kernel message, look for the changes to /proc/bus/usb/devices.

Since USB supports multiple identical devices, you can have multiple mice plugged in. You can get each mouse seperately, or you can get them all mixed together. You almost always want the mixed version, and that is what will be used together. You need to set up a device node entry for the mixed mice. It is customary to create the entries for this device in the /dev/input/ directory.

Use the following commands:

mkdir /dev/input mknod /dev/input/mice c 13 63

If you are unsure whether you are configuring the right mouse device, use cat /dev/input/mice (or other appropriate devices names). In case you do this for the correct mouse, you should see some bizarre looking characters as you move the mouse or click any of the buttons.

If you want to use the mouse under X, you have various options. Which one you select is dependent on what version of XFree86 you are using and whether you are using only USB for your mouse (or mice), or whether you want to use a USB mouse and some other kind of pointer device.

You need to edit the XF86Config file (usually /usr/X11R6/lib/X11/XF86Config or /etc/X11/XF86Config).

If you are using XFree86 version 4.0 or later, add an InputDevice section that looks like the following:

Section "InputDevice" Identifier "USB Mice" Driver "mouse" Option "Protocol" "IMPS/2" Option "Device" "/dev/input/mice" EndSection

or, if you want to use a wheel mouse, something like this may be more useful:

Section "InputDevice" Identifier "USB Mice" Driver "mouse" Option "Protocol" "IMPS/2" Option "Device" "/dev/input/mice" Option "ZAxisMapping" "4 5" Option "Buttons" "5" EndSection

Consult the current XFree86 documentation for a detailed explanation and more examples.

You also need to add an entry to each applicable ServerLayout Section. These are normally at the end of the configuration file. If you only have a USB mouse (or USB mice), then replace the line with the "CorePointer" entry with the following line:

InputDevice "USB Mice" "CorePointer"

If you want to use both a USB mouse (or USB mice) and some other kind of pointer device, then add (do not replace) the following line to the applicable ServerLayout sections:

InputDevice "USB Mice" "SendCoreEvents"

If you are using only a USB mouse (or USB mice) with XFree86 3.3, edit the Pointer section so that it looks like the following:

Section "Pointer" Protocol "IMPS/2" Device "/dev/input/mice" EndSection

If you are trying to use a USB mouse (or USB mice) in addition to another pointer type device with XFree86 3.3, then you need to use the XInput extensions. Keep the existing Pointer (or modify it as required for the other device if you are doing an initial installation), and add the following entry (anywhere sensible, ideally in the Input devices area):

Section "Xinput" SubSection "Mouse" DeviceName "USB Mice" Protocol "IMPS/2" Port "/dev/input/mice" AlwaysCore EndSubSection EndSection

Restart the X server. If you don't have any mouse support at this point, remember that Ctrl-Alt-F1 will get you a virtual terminal that you can use to kill the X server and start debugging from the error messages.

If you want to use the mouse under gpm, run (or kill and restart if it is already running) gpm with the following options. gpm -m /dev/input/mice -t imps2 (as superuser). You can make this the default if you edit the initialisation files. These are typically named something like rc.d and are in /etc/rc.d/ on RedHat distributions.

If you have both a USB mouse (or USB mice) and some other kind of pointer device, you may wish to use gpm in repeater mode. If you have a PS/2 mouse on /dev/psaux and a USB mouse (or USB mice) on /dev/input/mice, then the following gpm command would probably be appropriate: gpm -m /dev/input/mice -t imps2 -M -m /dev/psaux -t ps2 -R imps2. Note that this will make the output appear on /dev/gpmdata, which is a FIFO and does not need to be created in advance. You can use this as the mouse "device" to non-X programs, and both mice will work together.

Table 12-1. Arguments for the -t and -R option of gpm.

option	description
ms	MicroSoft compatible serial mouse
ps2	PS/2 or C&T 82C710
bm	Logitech bus mouse
bm	ATI XL bus mouse
mb	MicroSoft bus mouse
msc	Mouse Systems serial mouse
logi	older mouse
mman	Mouse Man protocol, serial Logitech mouse
sun	SUN mouse, three button
ms3	Intellimouse with wheel, at serial port
imps2	Intellimouse with wheel, at PS/2 port
pnp	PnP mice, alternative to ms
mm	MM series
bare	oldest serial two button mouse

12.17.10. Macintosh PowerBooks

PowerBooks have a trackpad and only one button, although you can plug in external multi-button USB mice. The usual thing is to map a couple of keys on the keyboard to the middle and right mouse buttons; your Linux distribution should come with instructions on how to configure this (it's not specific to laptops, as all Apple mice are single-button).

If you are using the Xpmac server, the default is option-1 and option-2, and you can change this by passing -middlekey <keycode> -rightkey <keycode> arguments to Xpmac, and -nooptionmouse if you don't want the option key to be needed.

If you are using XFree86, you pass adb_buttons=<middlekey>,<rightkey> kernel arguments (no option is required). I use adb_buttons=58,55 to map the option and Apple/command keys (which are little-used in Linux); use e.g. xev to find out the keycode for a given key.

12.18.1. Linux Compatibility Check

Start by reading the Battery-Powered-mini-HOWTO.

For APM to work the machine's firmware must implement the APM Specification. Linux supports versions 1.0 through 1.2 of the standard. To work with Linux the APM BIOS must support 32-bit protected mode connections.

To display information about the APM BIOS on your system you can run dmesg | grep apm command or look in the /proc/apm file.

12.18.2. Introduction

APM support consists of two parts: kernel support and user-land support.

12.18.3. Caveats

If you use another operating system at the same computer make sure that its "suspend" and "hibernate" features don't write to partitions that are used by Linux.

12.18.4. Troubleshooting

If your machine worked with 2.0.x kernels but not with the 2.2.x series, take this advice from Klaus Franken kfr_AT_klaus.franken.de : "The default changed in 2.2. Search in the init-scripts for halt and change it to halt -p or poweroff. See man halt , if you don't have this option you need a newer version of halt." You may find it in the SysVinit package.

On some new machines (for instance HP Omnibook 4150 - 366 MHz model) when accessing /proc/apm, you may get a kernel fault general protection fault: f000. Stephen Rothwell explaines: "This is your APM BIOS attempting to use a real mode segment while in protected mode, i.e. it is a bug in your BIOS. .. We have seen a few of these recently, except all the others are in the power off code in the BIOS where we can work around it by returning to real mode before attempting to power off. Here we cannot do this."

According to Kernel docs Documentation/Configure.help: "Some other things you should try when experiencing seemingly random, weird problems:

1. make sure that you have enough swap space and that it is enabled swapon -s.

2. pass the no-hlt option to the kernel.

3. switch on floating point emulation in the kernel and pass the no387 option to the kernel.

4. pass the floppy=nodma option to the kernel.

5. pass the mem=4M option to the kernel (thereby disabling all but the first 4 MB of RAM).

6. make sure that the CPU is not over clocked (doesn't seem suitable for mobile machines).

7. read the sig11 FAQ .

8. disable the cache from your BIOS settings.

9. install a fan for the video card or exchange video RAM (doesn't seem suitable for mobile machines).

10. install a better fan for the CPU (doesn't seem suitable for mobile machines).

11. exchange RAM chips (doesn't seem suitable for mobile machines).

12. exchange the motherboard (doesn't seem suitable for mobile machines).

12.18.5. APM and PCMCIA

From the PCMCIA-HOWTO: "Card Services can be compiled with support for APM (Advanced Power Management) if you've configured your kernel with APM support. ... The PCMCIA modules will automatically be configured for APM if a compatible version is detected on your system. Whether or not APM is configured, you can use cardctl suspend before suspending your laptop, and cardctl resume after resuming, to cleanly shut down and restart your PCMCIA cards. This will not work with a modem that is in use, because the serial driver isn't able to save and restore the modem operating parameters. APM seems to be unstable on some systems. If you experience trouble with APM and PCMCIA on your system, try to narrow down the problem to one package or the other before reporting a bug. Some drivers, notably the PCMCIA SCSI drivers, cannot recover from a suspend/resume cycle. When using a PCMCIA SCSI card, always use cardctl eject prior to suspending the system.".

12.18.6. APM and Resuming X Windows

Some machines have APM firmware that fails to save and restore display controller chip registers across a suspend. Earlier versions of the XFree86 X server did not restore the screen properly after resume, a problem which was addressed by Linux Laptops. However, contemporary versions of XFree86 mostly do the right thing.

Sometimes X and APM don't work smoothly together. The machine might even hang. A recommendation from Steve Rader: Some linux systems have their X11 server hang when doing apm -s. Folks with this affliction might want to switch to the console virtual terminal and then suspend chvt 1; apm -s as root, or, more appropiately sudo chvt 1; sudo apm -s. I have these commands in a script, say, my-suspend and then do xapmload --click-command my-suspend .

12.18.7. Software Suspend

Software suspend enables the possibility of suspending a machine. It doesn't need APM. You may suspend your machine by either pressing Sysrq-d or with swsusp or shutdown -z (patch for sysvinit needed). It creates an image which is saved in your active swaps. By the next booting the kernel detects the saved image, restores the memory from it and then it continues to run as before you've suspended. If you don't want the previous state to continue use the noresume kernel option.

Software suspends may even be better than hibernate, because now I can suspend my Linux system, boot into Microsoft Windows, perform a few illegal operations and be shut down, and then restart my Linux setup exactly where I left off! This is something that cannot be done with hibernation, since that always restores the last state that you suspended from, be it Microsoft Windows or Linux. So if I want to switch to Microsoft Windows to play games or do anything else, I can leave my Linux desktop exactly as it is and return to how I left it.

In recent 2.6 kernels SoftWareSuspend is part of the kernel. You may find it in the section Power Management. But there are also backports to 2.4 available.

Since the original Software Suspend code was written by Gabor Kuti and Pavel Machek back in 1998, three different implementations have been created for the 2.6 kernel, all forks of the same original codebase.

TuxOnIce, former known as Software Suspend 2, has a long feature list, including the ability to cancel a suspend by pressing Escape, image compression to save time and space, a versatile plugin architecture, and support for machines with Highmem, preemption and SMP.

12.18.8. Tips and Tricks

12.19.1. Related Documentation

1. ACPI-HOWTO I by Emma Jane Hogbin

2. ACPI-HOWTO II by Ariel Glenn. This document describes how to compile, install, and use the ACPI driver for Linux and its associated applications.

3. ACPI-HOWTO III

4. ACPI4Linux Project and its Wiki

5. ACPI Info provides the ACPI specification.

6. Section 12.3 the CPU chapter of this guide

12.19.2. ACPI Details

ACPI stands for Advanced Configuration and Power Interface. This is a specification by Toshiba, Intel and Microsoft. Besides many other things it also defines power management. This is why it is often compared to APM.

You might use the following parameters (with the appropriate changes) in your boot loader configuration file (e.g. /etc/lilo.conf to experiment with ACPI and APM, when compiled in the same kernel. Usage of APM and ACPI at the same time doesn't work, see Kernel docs for details.

append="acpi=on apm=off"

The Linux ACPI Project is committed to the development of fundamental ACPI (Advanced Configuration and Power Interface) components for Linux. This includes a generic ACPI table parser, AML interpreter, bus and device drivers, policy, user interface, and support tools.

The E-AcpiPower epplet is based on E-Power. It is modified to read battery status information using the new acpi kernel module, making it much more accurate and reliable than the old APM method.

TCL/TK script which allows setting the ACPI CPU performance state using a graphical interface under Linux.

Linux ACPI client is a command-line tool, similar to the apm command, that provides information on battery status, AC power, and thermal readings.

12.21.1. Smart Battery Support

The sbsutils package is a set of utilities programs to handle the Smart Battery on laptops, it offers Linux kernel & ACPI support for the Smart Battery System found in some laptop computers.

12.21.2. How to Improve Battery Uptime

These are the most important factors which have influence on the battery uptime. Please see the appropriate chapters for power saving tips:

• Section 12.3 CPU

• fan

• Section 12.22 memory

• Section 12.6graphics card

• Section 12.33 hard disk drive

• Section 12.32 optical drive

Getting your computer to use the least amount of power can be problematic. Intel's http://www.linuxpowertop.org/index.php project provides information on reducing power usage, tips, and tricks for Intel-based computers running Linux. As a first step, Intel has released PowerTOP, a tool that helps you find what software is using the most power. By fixing (or closing) these applications or processes, you can immediately see the power savings in the tool. You'll also see the estimated time left for battery power if you are running a laptop. The Tips & Tricks page has fixes for a lot of the issues that are already found.

12.24.1. Definitions

First some definitions. There is a difference between docking station and port replicator.

I use the term docking station for a box which contains slots to put some interface cards in, and space to put a harddisk, etc. in. This box can be permanently connected to a PC. A port replicator is just a copy of the laptop ports which may be connected permanently to a PC.

12.24.2. Other Solutions

I don't use a docking station myself. They seem really expensive and I can't see any usefulness. Alright you have to deal with some more cables, but is it worth so much money? Docking stations are useful in an office environment when you have a permanent network connection, or need the docking station's expansion bus slots (e.g. for some excotic SCSI device).

Also all docking stations I know are proprietary models, so if you change your laptop you have to change this device, too. I just found one exception a docking station which connects to your laptop via IrDA® the IRDocking IR-660 by Tekram . It supports these connectors: 10Base-T (RJ-45); PS/2 Keyboard; PS/2 Mouse; 25-Pin Printer Port (LPT); IR Transceiver; Power (6 VDC). So it seems that a VGA port and a port to connect a desktop PC directly are missing. This device should work with Linux/IrDA®, though I couldn't check it out.

I would prefer to buy a PC instead and connect it via network to the laptop.

Or use an external display, which usually works well as described above, and an external keyboard and mouse. If your laptop supports an extra PS/2 port you may use a cheap solution a Y-cable, which connects the PS/2 port to an external keyboard and an external monitor. Note: Your laptop probably has support for the Y-cable feature, e.g. the COMPAQ Armada 1592DT.

12.24.3. Docking Station Connection Methods

AFAIK there are four solutions to connect a laptop to a docking station:

1. SCSI port (very seldom)

2. parallel port

3. (proprietary) docking port (common)

4. USB (often offered by third party manufacturers)

From Martin J. Evans "The main problem with docking stations is getting the operating system to detect you are docked. Fortunately, you can examine the devices available in /proc and thus detect a docked state. With this in mind a few simple scripts is all you need to get your machine configured correctly in a docked state.

You may want to build support for the docking station hardware as modules instead of putting it directly into the kernel. This will save space in your kernel but your choice probably largely depends on how often you are docked.

1) Supporting additional disks on the docking station SCSI card

To my mind the best way of doing this is to:

1. Either build support for the SCSI card into the kernel or build it as a module.

2. Put the mount points into /etc/fstab but use the "noauto" flag to prevent them from being mounted automatically with the mount -a flag. In this way, when you are docked you can explicitly mount the partitions off any disk connected to the docking station SCSI card.

2) Supporting additional network adaptors in the docking station

You can use a similar method to that outlined above for the graphics card. Check the /proc filesystem in your rc scripts to see if you are docked and then set up your network connections appropriately. "

Once you determine this information, you may use a script, similar to the following example, to configure the connection to your docking station at startup. The script is provided by Friedhelm Kueck:

# check, if laptop is in docking-station (4 PCMCIA slots available) # or if it is standalone (2 slots available) # Start after cardmgr has started # # Friedhelm Kueck mailto:fk_AT_impress.de # 08-Sep-1998 # # Find No. of Sockets SOCKETS=`tail -1 /var/run/stab | cut -d ":" -f 1` case "$SOCKETS" in "Socket 3") echo Laptop is in Dockingstation ... echo Disabeling internal LCD Display for X11 echo cp /etc/XF86Config_extern /etc/XF86Config # # Setup of PCMCIA Network Interface after start of cardmgr # echo echo "Setting up eth0 for use at Network ..." echo /sbin/ifconfig eth0 10.1.9.5 netmask 255.255.0.0 broadcast 10.1.255.255 /sbin/route add -net 10.1.0.0 gw 10.1.9.5 /sbin/route add default gw 10.1.10.1 ;; "Socket 1") echo Laptop is standalone echo Disabling external Monitor for X11 cp /etc/XF86Config_intern /etc/XF86Config echo echo Network device NOT setup ;; esac

12.24.4. Universal USB Port Replicators

I have used a Typhoon USB 2.0 7in1 Docking Station made by Anubis P/N 83057 to check the Linux compatibility of such devices. Actually this device should be named port replicator, because it does not have any extension slots. This device doesn't have a VGA port to connect to an external display. Only a few USB docking stations have this feature. It would be nice to get a report whether a VGA port works or not. Tested with laptop COMPAQ M700 (USB 1.1) and custom made kernel 2.6.1. Note the port replicator didn't work with an Apple PowerBook G4.

How does its different ports work with Linux:

• USB 2.0 A-type downstream: works with external hard disk and mouse out of the box

• USB 2.0 A-type downstream: see above

• PS/2 keyboard: works out of the box

• PS/2 mouse: works, but for 2.6 Kernels you have to specifiy the right mouse protocol psmouse_proto=imps (if psmouse is compiled as a module).

• serial port: tested with serial mouse, doesn't seem to work, /dev/ttyUSB0 was assigned

• parallel port: tested, device /dev/usb/usblp0 assigned, works e.g. with HP LaserJet 2100

• LAN: usbnet loads, device eth1 was assigned, ifconfig or pump configures the network device

• transfer port aka host link: works with usbnet module, use ifconfig usb0 to configure the network interface, (USB 1.1 host link B-type) untested

Here is the output of dmesg for the Typhoon port replicator:

hub 1-0:1.0: new USB device on port 1, assigned address 26 hub 1-1:1.0: USB hub found hub 1-1:1.0: 4 ports detected hub 1-1:1.0: new USB device on port 3, assigned address 27 hub 1-1.3:1.0: USB hub found hub 1-1.3:1.0: 4 ports detected hub 1-1:1.0: new USB device on port 4, assigned address 28 eth1: register usbnet at usb-0000:00:07.2-1.4, ASIX AX8817x USB 2.0 Ethernet hub 1-1.3:1.0: new USB device on port 1, assigned address 29 usb0: register usbnet at usb-0000:00:07.2-1.3.1, Prolific PL-2301/PL-2302 hub 1-1.3:1.0: new USB device on port 2, assigned address 30 drivers/usb/class/usblp.c: usblp0: USB Bidirectional printer dev 30 if 0 alt 1 proto 2 vid 0x067B pid 0x2305 hub 1-1.3:1.0: new USB device on port 3, assigned address 31 pl2303 1-1.3.3:1.0: PL-2303 converter detected usb 1-1.3.3: PL-2303 converter now attached to ttyUSB0 (or usb/tts/0 for devfs) hub 1-1.3:1.0: new USB device on port 4, assigned address 32 HID device not claimed by input or hiddev hid: probe of 1-1.3.4:1.0 failed with error -5 input: Composite USB PS2 Converter USB to PS2 Adaptor v1.09 on usb-0000:00:07.2-1.3.4 HID device not claimed by input or hiddev hid: probe of 1-1.3.4:1.1 failed with error -5 input: Composite USB PS2 Converter USB to PS2 Adaptor v1.09 on usb-0000:00:07.2-1.3.4

12.25.1. Related Documentation

1. PLIP-mini-HOWTO

2. Networking-HOWTO

3. Ethernet-HOWTO

12.25.2. Connection Methods

Almost all recent laptops are equipped with a built-in network card. This chapter shows some methods to connect older laptops without internal network cards.

12.25.3. Wake-On-LAN

Wake-On-LAN works with some laptops equipped with built-in network cards. Wake-On-LAN is the generic name for the AMD "Magic Packet" technology. It's very similar to the PCMCIA modem "wake on ring" signal line. The basic idea is that the network adapter has a very-low-power mode to monitor the network for special packet data that will wake up the machine. The etherwake package as well as the Wakeonlan Perl script are able to send 'magic packets' to wake-on-LAN enabled ethernet adapters and motherboards, in order to switch on remote computers. You may use ethtool to configure some special Wake-On-LAN settings.

12.26.1. Modem Types

There are three kinds of modems available: internal, PCMCIA card or external serial port modems. But some internal modems will not work with Linux these modems are usually called WinModem. This is caused by non-standard hardware. So you have to use either a PCMCIA card modem or an external modem (serial or USB). The LinModem-HOWTO by Sean Walbran provides a detailed instruction how to deal with these kind of modems. My pages about Internal Modems in Laptops and miniPCI Devices in Laptops provide a survey about the modem controllers used in different laptops.

Quotation from the Kernel-FAQ: "9.Why aren't WinModems supported? (REG, quoting Edward S. Marshall) The problem is the lack of specifications for this hardware. Most companies producing so-called WinModems refuse to provide specifications which would allow non-Microsoft operating systems to use them. The basic issue is that they don't work like a traditional modem; they don't have a DSP, and make the CPU do all the work. Hence, you can't talk to them like a traditional modem, and you -need- to run the modem driver as a realtime task, or you'll have serious data loss issues under any kind of load. They're simply a poor design."

"Win modems are lobotomized modems which expect Windows to do some of their thinking for them. If you do not have Windows, you do not have a connection. "

Anyway, I have set up a page collecting information on laptops with internal modems at TuxMobil - Hardware . Maybe it's possible to run such modems with MS-Windows9x/NT emulators like wine or VMware, but I don't know it.

The Linux WinModem Support and the Xmodem.org (former Gromit Winmodem) page are more or less the standard as to whether a modem is real or not, and also contain directions to getting drivers for the few winmodems that do have Linux drivers.

There is a driver for Lucent WinModems available. LucentPCI (binary only) driver, for PCI driven internal modems, see Linux WinModem Support and the LTModem diagnostic tool.

12.26.2. Caveats

Pay attention to the different kinds of phone lines: analog and ISDN. You can't connect an analog modem to an ISDN port and vice versa. Though there might be hybrid modems available. Connecting to the wrong port may even destroy your modem. Trick: If you are looking for an analog phone port in an office building which is usually wired with ISDN, take a look at the fax lines, they are often analog lines.

If your machine features an internal modem as well as an internal ethernet card, pay also attention to plug the right cable into the plug. Otherwise you may damage your hardware easily. It may even cause a fire.

For tracking the packets on PPP you may use pppstats. Or pload this provides a graphical view of the traffic (in and out) of the PPP connection. It is based on athena widgets hence is very portable. It also uses very little CPU time.

12.28.1. Linux Compatibility Check

If unsure about the right SCSI support, compile a kernel with all available SCSI drivers as modules. Load each module step by step until you get the right one.

12.28.2. Related Documentation

1. SCSI-2.4-HOWTO

12.28.3. Survey

There is no current x86 laptop yet with a SCSI harddisk. Though there have been two models with a built in SCSI port: Texas Instruments TI 4000 and HP OmniBook 800. Maybe the PowerBook G3 has a SCSI disk, but I didn't check this yet. The old Apple Powerbook Duo models had a SCSI hard disk.

For other models, if you need SCSI support you may get it by using a SCSI-PCMCIA card or via a SCSI adapter in a docking station.

12.29.1. Linux Compatibility Check

You should get information about the USB controller with cat /proc/pci and about USB devices with cat /proc/bus/usb/devices.

12.29.2. Miscellaneous

Newer laptops come equipped with the Universal Serial Bus - USB. The following USB devices are available, not all of them are fully supported by Linux yet: keyboard, mouse, printer, tablet, camera, cpia, webcam, MP3 player, modem, wireless LAN, audio, jukebox, scanner, storage (hard drive, memory stick), floppydrive, ZIP, Super Disk - LS 120, compact flash reader, CD, BlueTooth, ethernet, serial, joystick, USB Host-to-Host Cable, hub .

Visit the USB Linux home page. Also I have set up a page collecting information about laptops and mobile devices using USB at the TuxMobil - Mobile Hardware Survey .

Please note, I have got a report that the power by a laptop via USB is not enough for some kind of devices, e.g. Web Cams or hard disks. But it seems to depend on the laptop and the specific device. With desktop Linux machines these USB devices work flawlessly, but with mobile devices not.

12.31.1. Linux Compatibility Check

Usually there are no problems connecting a floppy drive to a Linux laptop. But with a laptop floppy drive you may sometimes not be able to use every feature. I encountered the superformat command (from the fdutils package) couldn't format more than 1.44MB with my HP OmniBook 800. You may also have difficulty when the floppy drive and CD drive are mutually exclusive, or when the floppy drive is a PCMCIA device (as with the Toshiba Libretto 100). With older laptops, there might be a minor problem if they use a 720K drive. As far as I know all distributions come with support for 1.44M (and sometimes 1.2M) floppies only. Though it's possible to install Linux anyway. Please see Installation chapter. Please see kernel documentation for boot time parameters concerning certain laptop floppy drives, for instance IBM™ ThinkPad. Or man bootparam .

12.32.1. CD-ROM

---

12.32.1.2. Introduction

Most notebooks today come with CD drives. If floppy and CD drive are swappable they are usually mutually exclusive, however many vendors (HP, Dell) provide cables which allow the floppy module to be connected to the parallel port. Sometimes the CD drives comes as external PCMCIA device (e.g. SONY), or as SCSI device (e.g. HP OmniBook 800), USB device (e.g. SONY), or as Firewire (e.g. SONY VAIO VX71P). Such an external devices might bear problems to install Linux from it.

As far as I know there are SONY DiscMans available which have a port to connect them to a computer or even a SCSI port. I found an article published by Ziff-Davis Publishing Company (September 1996 issue, but missed to note the URL) written by Mitt Jones: "Portable PC Card CD-ROM drives transform laptops into mobile multimedia machines", which listed: Altec Lansing AMC2000 Portable Multimedia CD-ROM Center; Axonix ProMedia 6XR; CMS PlatinumPortable; EXP CDS420 Multimedia Kit; H45 QuickPCMCIA CD; Liberty 115CD; Panasonic KXL-D740; Sony PRD-250WN CD-ROM Discman.

To here music from internal CD drives usually works without problems. But note:

Some notebooks come with an external CD drive, you need an extra cable to connect the sound output of the drive to the sound input of the notebook.

12.32.2. CD-RW

Most notebooks today even come with internal or external CD writers. The internal usually work, see CD-Writing-HOWTO for details. But with the different external (PCMCIA, Firewire, USB) drives you probably need some tweaking.

12.32.3. DVD Drive

regionset adjusts and shows the region code of DVD drives.

Universal Disk Format (UDF) Driver : "UDF is a newer CDROM filesystem standard that's required for DVD roms. It's meant to be a replacement for the ISO9660 filesystem used on today's CDROMs, but the immediate impact for most will be DVD. DVD multimedia cdroms use the UDF filesystem to contain MPEG audio and video streams. To access DVD cdroms you would need a DVD cdrom drive, the kernel driver for the cdrom drive, some kind of MPEG video support, and a UDF filesystem driver (like this one). Some DVD cdroms may contain both UDF filesystems and ISO9660 filesystems. In that case, you could get by without UDF support."

DVD Video

DVD formats:

Digital Versatile Disc DVD-5 4.4GB 1side 1 coat ~ 2h video DVD-9 8.5GB 1side 2 coat ~ 4h video DVD-10 9.4GB 2side 1 coat ~ 4.5h video DVD-18 17 GB 2side 2 coat ~ 8h video

12.33.1. Linux Compatibility Check

Useful programms are hdparm, dmesg, fsck and fdisk .

12.33.2. Utilities

The smartmontools package contains two utility programs (smartctl and smartd) to control and monitor storage systems using the Self-Monitoring, Analysis and Reporting Technology System (SMART) built into most modern ATA and SCSI hard disks. In many cases, these utilities will provide advanced warning of disk degradation and failure.

The hddtemp utility can read the temperature of S.M.A.R.T. hard disks.

12.33.3. Solid-State-Disks - SSDs

Solid-State-Disks (SSDS) need some optimization of the Linux file system before installing the operating system. Here are some tips and tricks for partition alignment. Also useful some tips from Theodore Ts'o about aligning filesystems to an SSD's erase block size.

12.33.4. Miscellaneous

Be careful when using your laptop abroad. I have heard about some destroyed harddisks due to a magnetic field emitted from the magnetic-holds at the backresttable of the seats in a German railway waggon.

Though I am quite satisfied with the quality of the hard disk in my laptop, when I removed it from the case I unintendedly dropped it. I recommend to be very careful.

12.33.5. Form Factors

AFAIK there are only two form factors for harddisks used in laptops. Since 2003 there is the 1.8" format. But much older and still the most common format is the 2.5" format. The 2.5" format seems to be available in different heights (Please note I couldn't verify this information yet):

• 18mm: laptops built before 1996 usually have drives 18mm high

• 12.7mm: I got a report about such disks but without a notebook model or manufacturer name

• 11mm: since 1996 the drives are 11mm high

• 9mm: many laptops, including the subnotebooks, now use a 9mm-high disk drive. The largest available in this format in late 1999 is IBM™ 12GN.

• 9.5mm: Toshiba Libretto L70 and L100 have a 9.5mm HD

• 8.45mm: Toshiba Libretto 20, 30, 50 and 60 have 8.45mm tall HDs

• 6.35mm: Toshiba Libretto L1000 has a 6.35mm HD

It might be possible to use a hard disk wich doesn't fit with some case modifications.

Some laptops come with a removable hard disk in a tray, for instance the KAPOK 9600D. There seem to be no SCSI drives for laptops available.

12.33.6. Manufacturer Tools

Some hard disk manufacturers offer dedicated tools to change hard disk parameters. For example Hitachi offers Drive Fitness Test (DFT), which provides a quick, reliable method to test SCSI and IDE hard disk drives, including Serial-ATA IDE drives. The Drive Fitness Test analyze function performs read tests without overwriting customer data. (However, Drive Fitness Test is bundled with some restoration utilities that will overwrite data.) The Feature Tool is a DOS-bootable tool for changing various ATA features.

12.35.1. Related Documentation

1. Wireless-HOWTO I,

2. Wireless-HOWTO II and

3. Wireless-HOWTO III.

12.35.2. Introduction

Many notebooks now come pre-equipped with wireless network support for the 802.11 protocol family. These devices are either based on miniPCI or PCMCIA. You may check that with either lspci or cardctl ident. External WLAN adapters are available as PCMCIA or CF-Cards and as USB devices. Details will follow in a later issue.

12.37.1. Linux Compatibility Check

To get the IrDA® port of your laptop working with Linux/IrDA® you may use StandardInfraRed (SIR) or FastInfraRed (FIR).

12.37.2. Related Documentation

1. Linux-Infrared-HOWTO

12.37.3. IrDA® Configuration - Survey

13.1.1. Card Families

1. Ethernet adapter

2. Token Ring adapter

3. Ethernet + Modem / GSM

4. Fax-Modem / GSM adapter

5. SCSI adapter

6. I/O cards: RS232, LPT, RS422, RS485, GamePort, IrDA®, Radio, Video

7. Memory cards

8. harddisks

9. 2.5" harddisk adapters

For desktops there are PCMCIA slots for ISA and PCI bus available.

13.1.2. Linux Compatibility Check

With the command cardctl ident you may get information about your card. If your card is not mentioned in /etc/pcmcia/config, create a file /etc/pcmcia/<MYCARD>.conf appropriately. Take an entry in the first file as a model. You may try every driver, just in case it might work, for instance the pcnet_cs supports many NE2000 compatible PCMCIA network cards. Note: it is a bad practice to edit /etc/pcmcia/config directly, because all changes will be lost with the next update. After creating /etc/pcmcia/<MYCARD>.conf restart the PCMCIA services. This may not be enough to get the card to work, but works sometimes for no-name network cards or modem cards. If you get a card to work or have written a new driver please don't forget to announce this to the developer of the PCMCIA-CS package David Hinds. Look at the current issue of SUPPORTED.CARDS to get information about supported cards.

Since not all cards are mentioned there, I have set up a Survey of PCMCIA/CardBus/CF Cards Supported by Linux.

13.7.1. External Readers

All external SD/MMC/CF-Card/Memory Stick readers are USB devices and work fine with the usb-storage module. The only caveat which might occur is that you may have difficulties to determine the device assignment. Just use dmesg after you have connected the reader. The command should show a SCSI device like /dev/sda1 assigned to the USB drive.

13.7.2. Internal Readers

Currently there are three kinds of devices available: USB, PCMCIA and PCI devices.

USB devices are seldom, but usually work out of the box. They behave like the external readers mentioned above.

Some readers are PCMCIA/CardBus devices. Often such a reader is located near the CardBus slot. The command cardctl ident will reveal these cards.

For some laptops and notebooks a driver for the Winbond's W83L518D and W83L519D SD/MMC card reader is available.

Some proprietary devices are not yet known to work with Linux. Except the readers built into the SHARP Linux PDAs, but the driver is closed source and available as a binary only for the ARM CPU.

13.8.1. Ethernet Devices

From kernel source 2.4.4:

• ADMtek AN986 Pegasus (eval. board)

• ADMtek ADM8511 Pegasus II (eval. board)

• Accton 10/100

• Billington USB-100

• Corega FEter USB-TX

• MELCO/BUFFALO LUA-TX

• D-Link DSB-650TX, DSB-650TX-PNA, DSB-650, DU-E10, DU-E100

• Linksys USB100TX, USB10TX

• LANEED Ethernet LD-USB/TX

• SMC 202

• SOHOware NUB Ethernet

13.8.2. BlueTooth Dongles

There are many dongles around. I have made some experience with the AIRcable for laptops and PDAs (e.g. SHARP's Zaurus models SL-5x00 and C-7x0). This USB dongle kit provides a fast, convenient way of connecting mobile Linux computers to another personal computer or notebook computer or mobile phone without any cabling. The AIRcable uses a BlueTooth connection without the need to set up a complicated BlueTooth configuration. For example: The AIRcable Zaurus-USB can be used for syncing the Zaurus (ZaurusManager, Intellisync), for Qtopia desktop and for network connections through the PC (Linux, Windows and Apple) running pppd. You may find further details and a survey of compatible mobile phones etc. at TuxMobil.

13.8.3. Port Replicators/Docking Stations

I do not have experience with these devices yet. But I expect that it will be difficult, if not impossible, to get them to run with Linux. For other kinds of port replicators and docking stations see the appropriate section in the laptop chapter.

13.9.1. Survey of Mobile Printers and Scanners

For a survey of ports and protocol to print via a mobile or stationary printer see the Different Environments chapter below.

1. CANON : BJC-80 (this printer can also be used as a scanner with the optional scan head!) David F. Davey wrote: "I finally have a Canon BJC-80 printer working properly with IrDA®. By properly I mean as a pseudo-PostScript device by way of ghostscript and a modified lpd.

   How:

   • linux-2.2.7-ac2-irda6

   • /proc/sys/net/irda/slot_timeout increased to 10 (essential or discovery fails)

   • ghostscript DEVICE set to bjc600

   • printcap includes:

     :xc#01777777:\ :fc#017:\ :fs#020000010002:

   • and lpd had to be modified to accept the ulong fs and to handle xc (which is documented but not coded in the lpd's I have looked at). "

   For further information look at his page BJC-80 .

   Tim Auckland wrote: Would my version of lpd help? unixlpr is a portable version of the lpr/lpd suite, compatible with traditional versions and RFC 1179 and with a couple of minor extensions, including the :ms= field (also seen in SunOS 4) and the ability to print directly to TCP connected printers without needing special filters. ms allows you to configure the tty using stty arguments directly, so if stty can handle the extended flags, my lpd should handle IrDA® out of the box. You can find the latest unixlpr here .

2. CANON : BJC-50 65% of the size of the BJC-80, Li-Ion battery included, and basically the same features as the BJC-80.

3. CANON : BJ-30

4. Citizen : CN-60

5. Pentax : Pocketjet

6. HP: DeskJet 340Cbi. This is a small, portable, low-duty-cycle printer. It prints either black, or color (3 color). I have had some problems with it loading paper. Overall, the small size and portability make it a nice unit for use with laptops. I use the HP 500/500C driver with Linux.

7. Olivetti: JP-90

8. MaxPoint : TravelScan, mobile scanner for the PCMCIA port.

AFAIK only the HP DeskJet 340Cbi and the BJC-80 machine have an infrared port. Pay attention to the supplied voltage of the power supply if you plan to travel abroad. I couldn't check the scan functionalities with Linux yet.

13.9.2. Scanner and OCR Software

SANE stands for Scanner Access Now Easy and is an application programming interface (API) that provides standardized access to any raster image scanner hardware (flatbed scanner, hand-held scanner, video- and still-cameras, frame-grabbers, etc.). The SANE standard is free and its discussion and development is open to everybody. The current source code is written for UNIX (including Linux) and is available under the GNU public license (commercial application and backends are welcome, too, however).

GOCR is optical character recognition software. It converts PGM files into ASC files.

For scanner drivers see Linux Drivers for Handheld Scanners.

13.9.3. Connectivity

There are different ways to connect a printer or scanner to a laptop. For printers usually: parallel port, serial port, USB and IrDA® port. For scanners usually: parallel port, SCSI (via PCMCIA or generic SCSI port), USB and PCMCIA port. All of them need the appropriate kernel drivers.

13.10.1. Keyspan PDA Serial Adapter

Single port DB-9 serial adapter, pushed as a PDA adapter for iMacs (mostly sold in Macintosh catalogs, comes in a translucent white/green dongle). Fairly simple device.

13.11.1. External Hard Disks

There are external hard disk cases with different connectors available: PCMCIA, USB and FireWire. Cases are available for 2.5" (laptop hard disks), 3.5" (desktop hard disks) and 5.25" (CD-Writer). All of them work very well together with Linux. Especially I like the cases for 2.5" hard disks, you may upgrade your current laptop hard disk and use the old one to put it into the external box to extend your hard disk space.

Caveat: After wake up from suspend mode, the external hard drive can't work. To cure this problem these remedies might help: Disconnect the external drive and then plug it in again. Or use an AC adapter to power the external drive. Though this seems unconvenient in a suspend situation. But since the external drive gets the power from the adapter, there is no disconnection from power as will be if power is provided from USB.

Caveat: Take care that the jumpers are set to Master. Almost all external hard disk cases will not work when the jumpers are set to Slave or Cable Select.

14.1.1. PCMCIA

From PCMCIA.ORG: " PCMCIA (Personal Computer Memory Card International Association) is an international standards body and trade association with over 200 member companies that was founded in 1989 to establish standards for Integrated Circuit cards and to promote interchangeability among mobile computers where ruggedness, low power, and small size were critical. As the needs of mobile computer users have changed, so has the PC Card Standard. By 1991, PCMCIA had defined an I/O interface for the same 68 pin connector initially used for memory cards. At the same time, the Socket Services Specification was added and was soon followed by the Card Services Specifcation as developers realized that common software would be needed to enhance compatibility. " The cards are available in different formats: Type I, II, III.

A quotation from the ../Documentation/Changes file: "PCMCIA (PC Card) support is now partially implemented in the main kernel source. Pay attention when you recompile your kernel. If you need to use the PCMCIA-CS modules, then don't compile the kernel's PCMCIA support. If you don't need to use the PCMCIA-CS modules (i.e. all the drivers you need are in the kernel sources), then don't compile them; you won't need anything in there. Also, be sure to upgrade to the latest PCMCIA-CS release." Further information you may get from the README-2.4 included with this package.

You may find an example kernel configuration for laptops in the Section 14.3.

14.1.2. Powermanagement

At the moment there are two power management drivers in the linux kernel (AFAIK). They each have different userspace interfaces /proc/apm/ and /dev/apmctl/ and /proc/acpi/ or something.

For further information see the page of John Fremlin . He has also written a program named powermanager.

With kernel 2.4 there is ACPI available, see ACPI chapter below.

The SuSE Powersave Daemon provides battery, temperature, AC, and CPU frequency control and monitoring along with proper suspend to disk/RAM and standby support with shell hooks that are easy to extend. It supports APM and ACPI machines and can control a hard disk's advanced power and acoustic management settings. It is perfect for laptops and workstations that need to run quietly with low power consumption, or switch to full performance mode if needed. Self definable power schemes give full control over power control features and allow easy and automatic switching between performance or power saving settings for each hardware component.

14.1.3. Hotplug

There is a new mailing list for developers interested in any aspects of the Linux kernel hotplug ability and functionality. This would include (but is not restricted to) USB, PCMCIA, SCSI, Firewire, and probably PCI developers. There is an initial SourceForge site.

Kernel Support for Hot-Plugable Devices

CONFIG_HOTPLUG Say Y here if you want to plug devices into your computer while the system is running, and be able to use them quickly. In many cases, the devices can likewise be unplugged at any time too. One well known example of this is PCMCIA- or PC-cards, credit-card size devices such as network cards, modems or hard drives which are plugged into slots found on all modern laptop computers. Another example, used on modern desktops as well as laptops, is USB. Enable HOTPLUG and KMOD, and build a modular kernel. Get agent software and install it. Then your kernel will automatically call out to a user mode "policy agent" (/sbin/hotplug) to load modules and set up software needed to use devices as you hotplug them.

14.2.1. PCMCIA

PCMCIAutils contains hotplug scripts and initialization tools necessary to allow the PCMCIA subsystem to behave (almost) as every other hotpluggable bus system (e.g. USB, IEEE1394). Please note that the kernel support for this new feature is only present since 2.6.13-rc1.

15.2.1. NetEnv

Do you use your laptop in different network environments? At home? In the office? At a customers site?

If yes, the small package "netenv" might be useful for you. When booting your laptop it provides you with a simple interface from which you can choose the current network environment. The first time in a new environment, you can enter the basic data and save it for later reuse.

Netenv sets up a file containing variable assignments which describe the current environment. This can be used by the PCMCIA setup scheme, e.g. like the one that comes with Debian/GNU Linux and perhaps others.

The netenv data can be used for things like:

1. Network Device: Configure the network device for different environments.

2. Choose a proper XF86Config: Think of using your laptop standalone with touchpad vs. connected to a CRT monitor along with an external mouse. For example, a wheel mouse could be used when docked, but the driver is not compatible with the normal trackpoint or touchpad.

3. Windowmanager: You can set up your windowmanager appropriate to the current location of your machine.

4. Printing Environment: The netenv data can easily be used to set up the printing environment.

Netenv is available at netenv home. It depends on dialog(1) for its menu interface. Netenv was developed by Gerd Bavendiek.

15.2.2. System Configuration Profile Management - SCPM

SuSE's System Configuration Profile Management - SCPM software allows you to switch configuration profiles. You can boot directly into one profile and then switch to another profile at run time. This is the successor of SuSE's older "scheme" management software.

15.2.3. ifplugd

ifplugd is a lightweight Linux daemon which configures the network automatically when a cable is plugged in and deconfigures it when the cable is pulled. It is primarily intended for usage with laptops. It relies on the distribution's native network configuration subsystem, and is thus not very intrusive.

15.2.4. divine

divine is an utility for people who use their machines in different networks all the time. "The idea is this:

• you describe the possible networks in /etc/divine.conf, including one or more machines that are probably up (routers and NIS servers come to mind).

• at boot time, you run divine.

• divine starts a thread that injects fake arp requests into the network. The thread will try again up to three times, pausing 1 second between retries. If the last try times out again, the thread will print an error message, leave the interface in the original state and exit cleanly.

• the main thread just looks for arp replies and exits if one is found.

• You have one resolv.conf per network, for example /etc/resolv.conf.default and /etc/resolv.conf.work. divine will symlink one of them to /etc/resolv.conf for you.

• You can specify a proxy server plus port and divine will write the proxy server to /etc/proxy. This can be evaluated inside your shell startup script, like this (zsh):

  export http_proxy="http://`</etc/proxy`/"

  The included perl script edit-netscape-proxy.pl will edit the proxy settings in your Netscape 4 preferences file.

• You can even specify an additional script to be run for each selection. You can use this to edit /etc/printcap or /etc/issue or do something else I forgot.

The point about divine in contrast to other solutions is that other solutions normally use ping or something like that. divine can check a large number of networks instantaneously, assuming that the machines you ping answer within one second (.4 seconds are normal on Ethernets). And pinging an unknown address will do an arp request anyway, so why not do an arp request in the first place?"

15.2.5. Mobile IP

From the Networking-HOWTO : "The term IP Mobility describes the ability of a host that is able to move its network connection from one point on the Internet to another without changing its IP address or losing connectivity. Usually when an IP host changes its point of connectivity it must also change its IP address. IP Mobility overcomes this problem by allocating a fixed IP address to the mobile host and using IP encapsulation (tunneling) with automatic routing to ensure that datagrams destined for it are routed to the actual IP address it is currently using."

Dynamics Mobile IP is a dynamical, hierarchical Mobile IP system for Linux operating system. The implementation enables a hierarchical model for IP mobility, thus decreasing the location update times as a mobile host moves. Dynamics system has been designed Wireless LAN technology in mind, and the system has optimized functionality for mobility in WLAN.

See also Linux and Mobile AdHoc Networks - MANETs.

15.2.6. DHCP/BootP

DHCP and BootP are also useful for working in different environments. Please see the DHCP-HOWTO .

15.2.7. PPPD Options

The pppd command can be configured via several different files: pppd file /etc/ppp/<your_options> .

15.2.8. /etc/init.d

You may even choose to do your configuration by editing the /etc/init.d files manually.

15.2.9. PCMCIA - Schemes

How can I have separate PCMCIA device setups for home and work? This is fairly easy using PCMCIA scheme support. Use two configuration schemes, called home and work. For details please read the appropriate chapter in the PCMCIA-HOWTO.

15.2.10. Bootloaders

15.2.11. X-Windows

From Steve <steve_AT_cygnet.co.uk> I got a configuration for X Windows with an external monitor: Note that I have introduced a neat trick! For my nice 17" monitor I start X11 with no options and get the default 16-bit 1152x864 display - but when using the LCD screen I specify a 15-bit display (startx -- -bpp 15) and get the correct 800x600 resolution automatically. This saves having to have two X11 config files.

15.2.12. More Info

Using a Laptop in Different Environments by Gerd Bavendiek . This article appeared in the August, 1997 issue of the Linux Gazette . This is an excellent, short technical article describing an easy way to setup your Linux notebook to boot into different network and printing configurations, especially useful for those who use their machines at home as well as other locations such as in the office, at school, or at a customer site.

15.3.1. Introduction

A short introduction about how to setup email on a laptop used at home (dial-up) and work (ethernet) by Peter Englmaier <ppe_AT_pa.uky.edu>:

15.3.2. Email with UUCP

Another possible solution for Email is to use UUCP. This software was made for disconnected machines, and is by far the easiest solution if you have several users on your laptop (we are talking about UNIX, remember?), each with his/her own account.

Unlike what most people think, UUCP does not need a serial connection: it works fine over TCP/IP, so your UUCP partner can be any machine on the Internet, if it is reachable from your network attachment point. Here is the UUCP sys for a typical laptop:

system mylaptop time any chat "" \d\d\r\c ogin: \d\L word: \P address uucp.mypartner.org port TCP

15.3.3. MailSync

Mailsync is a way of synchronizing a collection of mailboxes. The algorithm is a 3-way diff. Two mailboxes are simultaneously compared to a record of the state of both mailboxes at last sync. New messages and message deletions are propagated between the two mailboxes. Mailsync can synchronize local mailbox files in many formats and remote mailboxes over IMAP, POP, and IMAPS.

15.4.1. Useful Hardware

1. external harddisks

2. ZIP drive

Wade Hampton wrote: "You may use MS-DOS formatted ZIP and floppy discs for data transfer. You may be able to also use LS120. If you have SCSI, you could use JAZ, MO or possibly DVD-RAM (any SCSI disc that you could write to). I have the internal ZIP for my Toshiba 700CT. It works great (I use automount to mount it). I use VFAT on the ZIP disks so I can move them to Windows boxes, Linux boxes, NT, give them to coworkers, etc. One problem, I must SHUTDOWN to swap the internal CD with the ZIP."

15.4.2. Useful Software

15.4.3. DataConversion: AddressBooks, BookMarks, Todo-Lists, LDAP, Webpages

Transfering user data from one mobile device to another one, often requires some tools to extract the data from the source device before importing them into the target device, for example if you want to change your favorite mobile phone. Or if you want to use the addressbook from your mobile with your PDA, too. Here are some tools for bookmark conversion, addressbook migration, vCard extraction, LDAP merging and data conversion for PDAs and HandHeld PCs.

15.7.1. Introduction

I am not a computer security expert, but I think that security associated with mobile devices requires specific attention. Please read the Security-HOWTO by Kevin Fenzi and Dave Wreski for more information. I just collected some information below. Note, these means are just small steps to additional security, though I recommend that you use them.

Please read also the Linux Administrator's Security Guide (LASG) - FAQ by Kurt Seifried.

15.7.2. Means of Security

1. Antivirus policy: For Linux there are some anti virus programms available. Check the BIOS for an option to disable writing at the boot sector.

2. Laptop as a security risk itself: Since a laptop can easily be used to intrude a network, it seems a good policy to ask the system administrator for permission before connecting a laptop to a network.

3. Secure Protocol: When connecting to a remote server always use a secure protocol (for instance ssh) or tunneling tunnelv , pptp and APOP for POP accounts.

15.8.1. Means to Protect the Data

1. Encryption: the Linux Kernel offers different options. This Encrypted dual boot single hard drive system HOWTO, explains how to secure your system using nothing but Free Software. It was primarily written for people with a dual boot laptop, describing free tools to encrypt Microsoft Windows as well as Linux partitions.

2. Here are some Linux guides for laptops with built-in SmartCard-Reader.

3. User passwords: can be easily bypassed if the intruder gets physical access to your machine.

4. Hard Disk Passwords:

5. BIOS passwords: are easily crackable at least with older laptop models. Some manufacturers have now a second boot password (IBM).

   If you use a BIOS password/boot loader security, ADVERTISE IT! Paste a sticker (or tape a piece of paper) on the top of your laptop, saying something like:

   WARNING This laptop is password protected. The password can only be removed by an authorized [manufacturer's name] technician presented with proof of ownership. So don't even think of stealing it, because it won't do you any good.

6. Before you buy a second hand machine, check whether the machine seems to be stolen. I have provided a survey of databases for stolen laptops.

15.8.2. Means to Protect the Hardware

1. Laptop lock: Almost all (if not all) of the new laptops come with a slot for the lock, and if yours doesn't have one, most locks come with a kit to add a slot. One of Targus' Defcon locks even has a motion sensor, so you don't have to lock it up to a secure place, if you don't have one around.

   The only drawback that I can think of is that it takes a couple extra seconds to set up or pack up your laptop. It takes about 30 seconds to snap into place and makes it impossible to quickly walk away with the laptop. It won't stop a determined thief with the time to unscrew the legs of the desk or one that wanders around with a substantial pair of wire cutters in hand, but I feel pretty secure leaving the laptop on my desk while I go to meetings or lunch.

   Well known manufacturers of dedicated laptop locks are Kensignton and TARGUS.

2. Name plates: to reduce the possibility of theft, you may want to have a nameplate (name, phone, e-mail, address) made and affixed to the cover of the laptop. A nice one will cost you about $12, and can be made by any good trophy shop. They'll glue it on for you too. You could use double-sided tape instead, but glue is more permanent. So it's easy to return, but will look beaten and abused if these are removed. You may even make an engravement into the laptop cover (inside). And even better into every removable part (hard disk, battery, CD/DVD drive, power unit). If this machine ever gets to a repair office, I might get the machine back. Make sure you remember to update the plates if you move.

   If you don't mind marking up a piece of equipment worth several thousand dollars, make sure your laptop has some distinguishing feature that is easily recognizable, e.g. a bunch of stickers pasted on it. Not only does it make your laptop easier to recognize, my guess is that people would be less likely to steal it.

   It might even be useful to have a sticker that clearly says "Does Not Run Windows". This is at least an argument for having your bootloader stop at the bootloader prompt, rather than mosey onwards into a colorful XDM login.

3. Link xlock to apm services. What about setting a system such as when the laptop is unused for a while, instead of using normal apm service and suspend the machine, makes it run an xlock, disable the apm services in a way such that they do not suspend the machine automatically and start a 'laptop-protection daemon'. When the xlock disappears, the daemon is stopped and the apm services are restarted (so you might use the apm services yourself).

   In the case somebody unplugs the machine while under the xlock (without giving the password), then the daemon would detect it and could start doing some preventive action, such as: - playing a sound with maximum volume saying "I am getting stolen". - this daemon could also register to a fixed local server and do a ping every now and then. If the ping stops before the daemon unregister to the server, then server then can take other actions, such as sending SMS message, starting a video camera, in the room, etc. The apm services down would make the stealer unable to use the hot keys to suspend/stop the machine, isn't it?

4. You can change the "pollution preventer" logo at startup on AWARD BIOSES. See instructions from Sven Geggus. For IBM ThinkPads there is a dedicated DOS utility for burning your bizcard data into the BIOS boot screen.

5. Boot loader: a boot loader may be used to put your name and phone number (or whatever text you choose) into the boot sequence before the operating system is loaded. This provides a label that can't be removed by editing files or even doing a simple format of the harddisk. Some boot loaders (e.g. LILO) offer a password option, which is highly recommend (note without it's very easy to get root access).

6. Camouflage: if you carry a dedicated laptop bag, this can be spotted by a thief easily. So think about getting another kind of bag.

7. Serial Number: note the serial number in a secure place. This will be necessary if your laptop gets stolen.

8. Insurance: There are some dedicated insurances, see my page Database of Stolen Laptops.

9. Use of software that connects and identifies itself: As far as I know there was an old DOS utility that did something like this. It embedded itself into the bootsector and upon a certain keycombination it would throw a serial number onto the screen and play an audio code through the speaker (in case th monitor was no longer usable for whatever reason). You were supposed to register the serial number with the company that produced the utility.

   The laptop can send a mail with its real IP address if connected (mail with a print of ifconfig started by /etc/ppp/ip-up or by a cron job (if connected at a company-network).

10. Always remove the external devices and secure them in another place/room. Set the BIOS to boot on the hard disk first as a default setting and remove boot on other devices if possible. Also try to plug the power supply in the least accessible plug. So if your machine get stolen in your office the 'quick way' (e.g. during a 5 sec. cigarette break), the stealer won't perhaps have time to get the power supply, neither the time to get the drives. Perhaps he/she will end up with a less useful laptop and you may recover it.

11. Electronic Devices (Transponders): There are also devices available, which can be detected remote via satellites, see my page about stolen laptops for a survey.

15.8.3. The Day After

Your primary goal is to prevent your laptop from being stolen in the first place. Your secondary goal is to recover it after it is stolen. Report it to the police station ASAP. Check the local newsgroup (in case...) or even post in it.

I have provided a survey of databases for stolen laptops.

15.8.4. Resources

The chapter about theft protection has taken some advantages of ideas of Lionel "Trollhunter" Bouchpan-Lerust-Juery and a discussion, which has taken place in the debian-laptop mailing list in January 2001.

15.11.1. Console (Shell) and X11

The beeping of X11 windows can be configured to a shorter and lower pitched tone or even to a blunt "thump" with xset b ... options (a lower pitched tone is usually less annoying and distracting). Independently of that, most xterm-compatible windows and shells can be configured to make "visual bell" instead of "audio bell". For the console setterm -blength 0 and for X11 xset b off turns the bell off. See also the PCMCIA-HOWTO and much more details in the Visible-Bell-Howto.

15.11.2. PCMCIA

When starting your laptop with PCMCIA-CS configured correctly, this will be shown by two high beeps. If you want to avoid this put CARDMGR_OPTS="-q" into the PCMCIA configuration file, e.g. /etc/default/pcmcia for Debian/GNU Linux.

To avoid the dialtones during the modem dialing add

module "serial_cs" opts "do_sound=0"

to /etc/pcmcia/config.opts (from man serial_cs). This will disable speaker output completely, but the AT M command should let you selectively control when the speaker is active, e.g. AT M0 turns off the modem's speaker.

15.11.3. USB

usbmgr configuration file /etc/usbmgr.conf.

### BEEP # beep off # beep on

15.11.4. Hotplug

Add an entry into the configuration file /etc/sysconfig/hotplug.

HOTPLUG_BEEP="no"

15.11.5. Fan

Please make sure what you are doing, when configuring the fan. Your laptop may overheat and die, in case you have done something wrong. Just in case you want to check the fan try to cause a heavy CPU load, for example by issueing md5sum /dev/urandom. Now top will show an increased CPU load and the fan should began to run eventually. Note: usually you need to have been connected to power, otherwise the CPU might reduce load by itself. Also watch for the CPU temperature acpi -bt or cat /proc/acpi/thermal_zone/*.

For some laptop series there are Linux utilities available to control the fan and other features.

• Toshutils by Jonathan Buzzard for some Toshiba models.

• tpctl IBM ThinkPad configuration tools for Linux by Thomas Hood.

• i8k utils for DELL laptops.

15.11.6. Harddisk

To avoid unnecessary hard disk noise you may use the same techniques as described in the power saving chapter above. Modern laptop and notebook hard drives come with a so-called "Acoustic Management", just have a look into the manual to get an overview about the possible settings.

Some hard disk manufacturers offer dedicated tools, e.g. Hitachi's Feature Tool allows to change the drive Automatic Acoustic Management settings to the Lowest acoustic emanation setting (Quiet Seek Mode), or Maximum performance level (Normal Seek Mode). Also hdparm -M offers some Acoustic Management options.

15.11.7. Miscellaneous Applications

You may configure vi with the flash option, so it will use a flash in case of an error, instead of a bell. So just put this line into your .vimrc or at the vim prompt:

set flash

or try

set visualbell

16.5.1. Related Documentation

1. Coffee-HOWTO

2. AX-25-HOWTO

3. Serial-HOWTO

4. Serial-Programming-HOWTO

16.5.2. Applications

A Linux laptop can be used to collect data outside an office, e.g. geodesy data, sales data, network checks, patient data in a hospital and others. There is support for wireless data connections via cellular phone modems and amateur radio. I am not sure whether PCMCIA radio cards are supported, see Aironet Wireless Communications.

16.5.3. Specific Environments

There are laptops available with cases build for a rugged environment (even waterproof laptops). In some environments, for instance in hospitals, take care of the Electro-Magnetic-Compatibility of the laptop. This is influenced by many factors, for instance by the material used to build the case. Usually magnesium cases shield better than the ones made of plastics.