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 ).

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.

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.

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

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.

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

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

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.

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.

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

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.

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.

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.

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.

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, “Mobile Hardware in Detail” Hardware In Detail below. In general you may use:

If you don't want to install a complete Linux you may retrieve this information by using a micro Linux ( see Appendix A, Other Operating Systems 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.

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.

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 .

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:

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

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 .

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.

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.)

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.

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

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.

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.

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 :

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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:

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.

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

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.

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.

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.

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.

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."

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/

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.

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.

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

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.

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

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.

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.

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.

   model name : Intel(R) Pentium(R) III Mobile CPU 1000MHz

   model name : Pentium III (Coppermine)

#! /bin/sh

# /etc/init.d/slowcpu: slow down cpu or accelerate it via speedstep

test -e /proc/acpi/processor/CPU0/performance || exit 0

case "$1" in
    start)
    echo "Setting CPU0-Speed to: 733 MHz."
    echo 1 > /proc/acpi/processor/CPU0/performance
	;;
    stop)
    echo "Setting CPU0-Speed to: 1133 MHz."
    echo 0 > /proc/acpi/processor/CPU0/performance
	;;
    force-reload|restart)
	;;

    *)
	echo "Usage: $0 {start|stop}"
	exit 1
esac

exit 0

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.

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.

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.

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.

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.

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.

5.3.3. PCMCIA Card

1. Check your card with cardctl ident .

2. If your card is not in /etc/pcmcia/config, edit the 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.

3. A list of supported cards is included in the PCMCIA-CS package. The current list you may find at SUPPORTED.CARDS.

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

4. If you use a X11 GUI, you can use cardinfo to insert, suspend, or restart a PCMCIA card via a nice graphical interface.

Figure 12.1. Screenshot of cardinfo

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.

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.

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

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.

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.

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.

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:

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 .

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.

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 .

For playing CDs/DVDs from an external or internal CD/DVD drive, see chapter Section 32, “Optical Drives (CD/DVD)” CD/DVD Drive below.

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       

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.

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).

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.

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

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

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):

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.

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):

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.

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.

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 .

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

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.

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

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

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

InputDevice "USB Mice" "CorePointer"

InputDevice "USB Mice" "SendCoreEvents"

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

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

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.

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.

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

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.

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:

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.".

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 .

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.

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.

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.

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

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.