1
<!-- retain these comments for translator revision tracking -->
2
<!-- original version: 29467 untranslated -->
4
<sect1 id="supported-peripherals">
5
<title>Peripherals and Other Hardware</title>
8
Linux supports a large variety of hardware devices such as mice,
9
printers, scanners, PCMCIA and USB devices. However, most of these
10
devices are not required while installing the system.
12
</para><para arch="i386">
14
USB hardware generally works fine, only some
15
USB keyboards may require additional configuration
16
(see <xref linkend="usb-keyboard-config"/>).
18
</para><para arch="i386">
21
<ulink url="&url-hardware-howto;">Linux Hardware Compatibility HOWTO</ulink>
22
to determine whether your specific hardware is supported by Linux.
24
</para><para arch="s390">
26
Package installations from XPRAM and tape are not supported by this
27
system. All packages that you want to install need to be available on a
28
DASD or over the network using NFS, HTTP or FTP.
30
</para><para arch="mips">
32
The Broadcom BCM91250A evaluation board offers standard 3.3v 32 bit and 64
33
bit PCI slots as well as USB connectors.
35
</para><para arch="mipsel">
37
The Broadcom BCM91250A evaluation board offers standard 3.3v 32 bit and 64
38
bit PCI slots as well as USB connectors. The Cobalt RaQ has no support for
39
additional devices but the Qube has one PCI slot.
44
<sect1 arch="not-s390"><title>Purchasing Hardware Specifically for GNU/Linux</title>
48
There are several vendors, who ship systems with Debian or other
49
distributions of GNU/Linux
50
<ulink url="&url-pre-installed;">pre-installed</ulink>. You might pay more
51
for the privilege, but it does buy a level of peace of mind, since you can
52
be sure that the hardware is well-supported by GNU/Linux.
54
</para><para arch="m68k">
56
Unfortunately, it's quite rare to find any vendor shipping
57
new &arch-title; machines at all.
59
</para><para arch="i386">
61
If you do have to buy a machine with Windows bundled, carefully read
62
the software license that comes with Windows; you may be able to
63
reject the license and obtain a rebate from your vendor. Searching
64
the Internet for <quote>windows refund</quote> may get you some useful
65
information to help with that.
69
Whether or not you are purchasing a system with Linux bundled, or even
70
a used system, it is still important to check that your hardware is
71
supported by the Linux kernel. Check if your hardware is listed in
72
the references found above. Let your salesperson (if any) know that
73
you're shopping for a Linux system. Support Linux-friendly hardware
78
<sect2><title>Avoid Proprietary or Closed Hardware</title>
81
Some hardware manufacturers simply won't tell us how to write drivers
82
for their hardware. Others won't allow us access to the documentation
83
without a non-disclosure agreement that would prevent us from
84
releasing the Linux source code.
86
</para><para arch="m68k">
88
Another example is the proprietary hardware in the older
89
Macintosh line. In fact, no specifications or documentation have ever
90
been released for any Macintosh hardware, most notably the ADB
91
controller (used by the mouse and keyboard), the floppy controller,
92
and all acceleration and CLUT manipulation of the video hardware
93
(though we do now support CLUT manipulation on nearly all internal
94
video chips). In a nutshell, this explains why the Macintosh Linux
95
port lags behind other Linux ports.
99
Since we haven't been granted access to the documentation on these
100
devices, they simply won't work under Linux. You can help by asking
101
the manufacturers of such hardware to release the documentation. If
102
enough people ask, they will realize that the free software community
103
is an important market.
109
<sect2 arch="i386"><title>Windows-specific Hardware</title>
112
A disturbing trend is the proliferation of Windows-specific modems and
113
printers. In some cases these are specially designed to be operated by
114
the Microsoft Windows operating system and bear the legend <quote>WinModem</quote>
115
or <quote>Made especially for Windows-based computers</quote>. This
116
is generally done by removing the embedded processors of the hardware
117
and shifting the work they do over to a Windows driver that is run by
118
your computer's main CPU. This strategy makes the hardware less
119
expensive, but the savings are often <emphasis>not</emphasis> passed on to the
120
user and this hardware may even be more expensive than equivalent
121
devices that retain their embedded intelligence.
125
You should avoid Windows-specific hardware for two reasons. The first
126
is that the manufacturers do not generally make the resources
127
available to write a Linux driver. Generally, the hardware and
128
software interface to the device is proprietary, and documentation is
129
not available without a non-disclosure agreement, if it is available
130
at all. This precludes its being used for free software, since free
131
software writers disclose the source code of their programs. The
132
second reason is that when devices like these have had their embedded
133
processors removed, the operating system must perform the work of the
134
embedded processors, often at <emphasis>real-time</emphasis> priority,
135
and thus the CPU is not available to run your programs while it is
136
driving these devices. Since the typical Windows user does not
137
multi-process as intensively as a Linux user, the manufacturers hope
138
that the Windows user simply won't notice the burden this hardware
139
places on their CPU. However, any multi-processing operating system,
140
even Windows 2000 or XP, suffers from degraded performance when
141
peripheral manufacturers skimp on the embedded processing power of
146
You can help this situation by encouraging these manufacturers to
147
release the documentation and other resources necessary for us to
148
program their hardware, but the best strategy is simply to avoid this
149
sort of hardware until it is listed as working in the
150
<ulink url="&url-hardware-howto;">Linux Hardware Compatibility HOWTO</ulink>.
156
<sect2 id="Parity-RAM">
157
<title>Fake or <quote>Virtual</quote> Parity RAM</title>
160
If you ask for Parity RAM in a computer store, you'll probably get
161
<emphasis>virtual parity</emphasis> memory modules instead of
162
<emphasis>true parity</emphasis> ones. Virtual parity SIMMs can often
163
(but not always) be distinguished because they only have one more chip
164
than an equivalent non-parity SIMM, and that one extra chip is smaller
165
than all the others. Virtual-parity SIMMs work exactly like non-parity
166
memory. They can't tell you when you have a single-bit RAM error the
167
way true-parity SIMMs do in a motherboard that implements
168
parity. Don't ever pay more for a virtual-parity SIMM than a
169
non-parity one. Do expect to pay a little more for true-parity SIMMs,
170
because you are actually buying one extra bit of memory for every 8
175
If you want complete information on &arch-title; RAM issues, and what
176
is the best RAM to buy, see the
177
<ulink url="&url-pc-hw-faq;">PC Hardware FAQ</ulink>.
179
</para><para arch="alpha">
181
Most, if not all, Alpha systems require true-parity RAM.