Portable computers may be divided into different categories. This is a subjective decision, but I try to do so. My groupings roughly follow the generally accepted marketing categories. The criteria could be:
Weight: Often expressed in terms like Portables, Laptops/Notebooks, Sub/Mini-Notebooks, Palmtops/PDAs. There is no standard method to define the weight of a laptop, therefore the data provided by the manufacturers (and which are given below) have to be considered as approximations. The question is how the power supply (wether external or internal) or swappable parts like CD and floppy drive, are included in the weight.
Most peripheral cables are appallingly heavy. If you get a subnotebook
and carry it around with a bunch of external drives, cables, and port
expander dongles and power converter, you may be lugging a heavier
bag than if it were all in one box. Subnotebooks are useful mainly
if you can afford to leave all the other junk behind.
Supported Operations Systems: proprietary versus open
Price: NoName versus Brand
Hardware Features: display size, harddisk size, CPU speed, battery type, etc.
Linux Support: graphic chip, sound card, infrared controller (IrDA), internal modem, etc.
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.,
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.
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.
Watches, digital pens, calculators, digital cameras, cellular phones and other wearables.
Due to a lack of support by some hardware manufacturers, not every feature of a laptop is always supported or fully operational. The main devices which may cause trouble are: graphic chip, IrDA port, sound card, PCMCIA controller , PnP devices and internal modem. Please try to get as much information about these topics before buying a laptop. But often it isn't quite easy to get the necessary information. Sometimes even the specifications or the hotline of the manufacturer aren't able to provide the information. Therefore I have included a Linux Compatibility Check chapter in the Hardware In Detail sections below.
Depending on your needs, you might investigate one of the vendors that provide
laptops pre-loaded with Linux. By purchasing a pre-loaded Linux laptop, much
of the guesswork and time spent downloading additional packages could be
avoided. See the
Linux Laptop Manufacturer Survey.
Besides its Linux features, there often are some main features which have to be considered when buying a laptop. For Linux features please see the Hardware In Detail section below.
Don't underestimate the weight of a laptop. This weight is mainly influenced by:
internal components, such as CD drive, floppy drive
material used for the case, usually they are either from plastics or from magnesium.
Laptops come with one of two types of displays: active matrix (TFT) and passive matrix (DSTN). 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 15". 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).
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.
Unfortenately most laptops come with a proprietary battery size. So they are not interchangeable between different models.
Linux doesn't support this CPU family yet. But there are some efforts at
ELKS. If you like, you may use
Minix one of the predecessors of Linux. Minix supports 8088 to 286 with as little as 640K memory. Actually there are some laptops with ELKS around, for instance the
This covers PCs based on Intel-compatible processors, including Intel's 386, 486, Pentium, Pentium Pro and Pentium II, and compatible processors by AMD, Cyrix and others. Most of the currently available laptops use Intel compatible CPUs and have quite good Linux support.
This covers Amigas and Ataris having a Motorola 680x0 processor for x>=2; with MMU. And the early Apple/Macintosh computers.
There was a long series of Apple PowerBooks and other laptops based on the m68k chip. Macintosh Portable (an ugly 16-pound first attempt); PowerBook 100, 140, 170, 145, 160, 180c, 165c, 520c, 540c, 550c, 190; Duo 210, 230, 250, 270c, 280. The PowerBook Duos were available at the same time as the PowerBooks, they were a sort of subnotebook, but were designed so that you could plug them into a base station (a DuoDock) with more RAM, peripherals, etcetera, so that they could also act as a desktop computer. The first PowerPC PowerBooks were the ill-starred PowerBook 5300 (after the 190) and the Duo 2300c.
For a complete list of all Macintosh computers ever made, with specifications, see
Note also that readers should *not* go to www.linuxppc.org for hardware compatibility with 68k laptops--as the name implies, LinuxPPC is only for PowerPC machines. The proper place to go for information on running Linux on m68k Macintoshes is:
In particular, their hardware compatibility list is at:
linux-m68k-status and it states in regards to laptops:
"Much like laptops of the Intel/Linux world, Mac laptops have generally different setups that can be very hard to figure out. Also, because of a general lack of machines to test, we are only aware of boots on the Powerbook 145, Powerbook 150, Powerbook 170, Powerbook 180, and Powerbook 190. Even if it boots, we currently have no support for Powerbook-style ADB, the APM support, or just about anything else on them. This means the only way to log in is with a terminal hooked up to the serial interface, this has been tested on the 170."
"Several Powerbooks have internal IDE which is supported. PCMCIA drivers will be forthcoming if someone can supply the necessary hardware information to write a driver. As always, an FPU is needed also. Many of the later models have the 68LC040 processor without FPU, and many of these processors are broken with respect to the FPU trap mechanism so they can't run regular Linux binaries even with FPU emulation. Current status on Powerbooks 140, 160, 165, 165c, 180c, 190, 520 and Duos 210, 230, 250, 270c, 280, and 280c is unknown."
Also there are two Atari laptops, for which I don't have enough information. The following quotations are from the
"The STacy was released shortly after the Mega ST to provide a portable means of Atari computing. STacy computers were shipped with TOS v1.04.
Designed to replace the STacy as the defacto portable ST computer, the ST Book brought the basic computing power of an ST to a lightweight notebook computer. This machine was only released in Europe and Atari only shipped a very small quantity. The ST Book was shipped with TOS v2.06."
Is there an Amiga notebook?
Although some driver support present in Intel based Linux is still missing for Linux PPC, it is a fully usable system for Macintosh PowerBooks. See
LinuxPPC for a current list of supported machines.
BTW: The team at
iMac Linux has managed to get the iMac DV to boot Linux to a usable point. You may get information about the iBook there as well.
Alpha, Sparc, Sparc64 architectures:
These are currently under construction. AFAIK there are only the Tadpole SPARC and ALPHA laptops, and some other ALPHA laptops available.
a very low-power CPU found in Rebel.com's popular NetWinder (some kind of mobile computer, too),
and actively supported in the Debian project, it is also in several
WinCE machines, such as HP's Jornadas. Only the lack of tech specs
prevents Linux from being ported to these tiny, long-battery-life
machines. A full-scale StrongARM-based laptop would make a superb
Linux platform, but none exists yet.
For PDAs with ARM/StrongARM CPU see the PDA chapter below.
Used in SGI mainframes and Cobalt Micro intranet appliances,
chips based on this architecture are used in many Wince machines.
Linux has been ported to a few of these, including the lovely little
Vadem Clio. Vadem has been admirably cooperative.
More about Linux on Wince boxes may be found at
At higher speed, a CPU consumes more power and generates more heat. Therefore, in many laptops a special low-power CMOS CPU is used. Usually, this special CPU doesn't use as much power as a similar processor used in a desktop. These special CPUs are also more expensive. As a side effect you may find that laptops with a desktop CPU often have a fan which seems quite loud.
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 had better not ever get blocked, or it will overhead 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 headaches and finger-aches. 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. 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. For German readers there is an online market place at
http://www.hardware.de, which offers a good survey about current prices for second hand machines.
If you travel abroad pay attention to the voltage levels which are supported by the power supply. Also the power supply is often one of the heavier parts of a laptop.
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 Hardware on Detail section below. In general you may use:
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 usually by dmesg or by looking into /var/log/messages.
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 database from Craig Hart at
http://members.hyperlink.net.au/~chart. From 2.1.82 kernels on you may use the lspci command from the pci-utils package.
To retrieve information about Plug-and-Play (PNP) devices use isapnp-tools .
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). 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."
The Lothar Project
is a Mandrake-related project to provide a GUIed interface to get at hardware
configuration information on Linux-based systems. It provides a
library for different system informations, too.
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.
If you encounter a device which is not yet supported by Linux, don't forget it's also possible to write a driver by yourself. You may look at the book from Alessandro Rubini, Andy Oram: Linux Device Drivers.
AFAIK there is no Linux tool like the DOS tools CHECK-IT, DR. HARD, SYSDIAG and others. These tools include many of the tests in one integrated suite. One of the best IMHO is the tool PC Diagnostics 95 made by Craig Hart
http://members.hyperlink.net.au/~chart . Despite the 95 in its name it's plain DOS, tiny (76KB programm and 199KB data) reliable and free. Unfortenately it contains no check for the IrDA port.
Please note this quotation from the disclaimer: "This program is written with the target audience being a trained, experienced technician. It is NOT designed to be used by those ignorant of computer servicing. Displays are not pretty but functional. Information is not explained since we are not trying to educate. This software should be considered to be just like any other tool in a tech's toolbox. It is to be applied with care, in the right situation, in order to find answers to specific problems. If you are an end user who is less than confident of dealing with computer hardware, this is probably not a program for you."
Laptop computers, unlike desktop machines, really do get used up.
Lithium batteries are good for no more than 400 recharge cycles,
sometimes much fewer. Keyboards wear out. LCD screen backlighting
grows dim. Mouse buttons fail. Worst of all, connectors get loose
as a result of vibration, causing intermittent failures (e.g. only
when you hit the <Enter> key). We have heard of a machine used on the
table in a train being shaken to unusability in one trip.
It's difficult to give any recommendations for a certain laptop model in general. Your personal needs have to be taken into account. Also the market is changing very quickly. I guess every three months a new generation of laptops (according to harddisk space, CPU speed, display size, etc.) comes into the market. So I don't give any model or brand specific recommendations.