ca/hardware/supported-peripherals.xml

<!-- retain these comments for translator revision tracking -->
<!-- $Id: supported-peripherals.xml,v 1.7 2004/01/05 17:08:24 mck-guest Exp $ -->

 <sect1 id="supported-peripherals">
 <title>Peripherals and Other Hardware</title>
<para>

Linux supports a large variety of hardware devices such as mice,
printers, scanners, PCMCIA and USB devices.  However, most of these
devices are not required while installing the system.

</para><para arch="i386">

USB keyboards may require additional configuration 
(see <xref linkend="usb-keyboard-config"/>).

</para><para>

This section contains information about peripherals specifically
<emphasis>not</emphasis> supported by the installation system, even
though they may be supported by Linux.

</para><para arch="i386">

Again, see the 
<ulink url="&url-hardware-howto;">Linux Hardware Compatibility HOWTO</ulink>
to determine whether your specific hardware is supported by Linux.

</para><para arch="i386">

USB hardware is supported by the flavor "bf2.4". If you find that you
cannot use some USB devices, you may upgrade to kernel 2.4.x later.

</para><para arch="i386">

Note that the stock kernels do not support serial ports numbered
greater than four (<filename>/dev/ttyS3</filename>).  You'll have to
either use the available ports, or else build a custom kernel (see
<xref linkend="rescue-replace-kernel"/>).

</para><para arch="s390">

Package installations from XPRAM and tape are not supported by this
system.  All packages that you want to install need to be available on a
DASD or over the network using NFS, HTTP or FTP.

</para>
</sect1>

 <sect1 arch="not-s390"><title>Purchasing Hardware Specifically for GNU/Linux</title>

<para>

There are several vendors, who ship systems with Debian or other
distributions of GNU/Linux pre-installed.  You might pay more for the
privilege, but it does buy a level of peace of mind, since you can be
sure that the hardware is well-supported by GNU/Linux.  

</para><para arch="m68k"> 

Unfortunately, it's quite rare to find any vendor shipping
new &arch-title; machines at all. 

</para><para arch="i386"> 

If you do have to buy a machine with Windows bundled, carefully read
the software license that comes with Windows; you may be able to
reject the license and obtain a rebate from your vendor.  See 
<ulink url="&url-windows-refund;"></ulink> for complete details.

</para><para>

Whether or not you are purchasing a system with Linux bundled, or even
a used system, it is still important to check that your hardware is
supported by the Linux kernel.  Check if your hardware is listed in
the references found above.  Let your salesperson (if any) know that
you're shopping for a Linux system.  Support Linux-friendly hardware
vendors.

</para>

  <sect2><title>Avoid Proprietary or Closed Hardware</title>
<para>

Some hardware manufacturers simply won't tell us how to write drivers
for their hardware. Others won't allow us access to the documentation
without a non-disclosure agreement that would prevent us from
releasing the Linux source code.

</para><para arch="m68k"> 

Another example is the proprietary hardware in the older
Macintosh line. In fact, no specifications or documentation have ever
been released for any Macintosh hardware, most notably the ADB
controller (used by the mouse and keyboard), the floppy controller,
and all acceleration and CLUT manipulation of the video hardware
(though we do now support CLUT manipulation on nearly all internal
video chips).  In a nutshell, this explains why the Macintosh Linux
port lags behind other Linux ports.

</para><para>

Since we haven't been granted access to the documentation on these
devices, they simply won't work under Linux. You can help by asking
the manufacturers of such hardware to release the documentation. If
enough people ask, they will realize that the free software community
is an important market.

</para>
</sect2>


  <sect2 arch="i386"><title>Windows-specific Hardware</title>
<para>

A disturbing trend is the proliferation of Windows-specific modems and
printers. In some cases these are specially designed to be operated by
the Microsoft Windows operating system and bear the legend
``WinModem'' or ``Made especially for Windows-based computers''. This
is generally done by removing the embedded processors of the hardware
and shifting the work they do over to a Windows driver that is run by
your computer's main CPU. This strategy makes the hardware less
expensive, but the savings are often <emphasis>not</emphasis> passed on to the
user and this hardware may even be more expensive than equivalent
devices that retain their embedded intelligence.

</para><para>

You should avoid Windows-specific hardware for two reasons. The first
is that the manufacturers do not generally make the resources
available to write a Linux driver. Generally, the hardware and
software interface to the device is proprietary, and documentation is
not available without a non-disclosure agreement, if it is available
at all. This precludes its being used for free software, since free
software writers disclose the source code of their programs. The
second reason is that when devices like these have had their embedded
processors removed, the operating system must perform the work of the
embedded processors, often at <emphasis>real-time</emphasis> priority,
and thus the CPU is not available to run your programs while it is
driving these devices. Since the typical Windows user does not
multi-process as intensively as a Linux user, the manufacturers hope
that the Windows user simply won't notice the burden this hardware
places on their CPU.  However, any multi-processing operating system,
even Windows 95 or NT, suffers from degraded performance when
peripheral manufacturers skimp on the embedded processing power of
their hardware.

</para><para>

You can help this situation by encouraging these manufacturers to
release the documentation and other resources necessary for us to
program their hardware, but the best strategy is simply to avoid this
sort of hardware until it is listed as working in the 
<ulink url="&url-hardware-howto;">Linux Hardware Compatibility HOWTO</ulink>.

</para>
</sect2>


  <sect2 id="Parity-RAM"><title>Fake or ``Virtual'' Parity RAM</title>
<para>

If you ask for Parity RAM in a computer store, you'll probably get
<emphasis>virtual parity</emphasis> memory modules instead of
<emphasis>true parity</emphasis> ones. Virtual parity SIMMs can often
(but not always) be distinguished because they only have one more chip
than an equivalent non-parity SIMM, and that one extra chip is smaller
than all the others. Virtual-parity SIMMs work exactly like non-parity
memory.  They can't tell you when you have a single-bit RAM error the
way true-parity SIMMs do in a motherboard that implements
parity. Don't ever pay more for a virtual-parity SIMM than a
non-parity one. Do expect to pay a little more for true-parity SIMMs,
because you are actually buying one extra bit of memory for every 8
bits.

</para><para>

If you want complete information on &arch-title; RAM issues, and what
is the best RAM to buy, see the 
<ulink url="&url-pc-hw-faq;">PC Hardware FAQ</ulink>.

</para><para arch="alpha"> 

Most, if not all, Alpha systems require true-parity RAM. 

</para>

  </sect2>

 </sect1>
1	<!-- retain these comments for translator revision tracking -->
2	<!-- $Id: supported-peripherals.xml,v 1.7 2004/01/05 17:08:24 mck-guest Exp $ -->
3
4	<sect1 id="supported-peripherals">
5	<title>Peripherals and Other Hardware</title>
6	<para>
7
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.
11
12	</para><para arch="i386">
13
14	USB keyboards may require additional configuration
15	(see <xref linkend="usb-keyboard-config"/>).
16
17	</para><para>
18
19	This section contains information about peripherals specifically
20	<emphasis>not</emphasis> supported by the installation system, even
21	though they may be supported by Linux.
22
23	</para><para arch="i386">
24
25	Again, see the
26	<ulink url="&url-hardware-howto;">Linux Hardware Compatibility HOWTO</ulink>
27	to determine whether your specific hardware is supported by Linux.
28
29	</para><para arch="i386">
30
31	USB hardware is supported by the flavor "bf2.4". If you find that you
32	cannot use some USB devices, you may upgrade to kernel 2.4.x later.
33
34	</para><para arch="i386">
35
36	Note that the stock kernels do not support serial ports numbered
37	greater than four (<filename>/dev/ttyS3</filename>). You'll have to
38	either use the available ports, or else build a custom kernel (see
39	<xref linkend="rescue-replace-kernel"/>).
40
41	</para><para arch="s390">
42
43	Package installations from XPRAM and tape are not supported by this
44	system. All packages that you want to install need to be available on a
45	DASD or over the network using NFS, HTTP or FTP.
46
47	</para>
48	</sect1>
49
50	<sect1 arch="not-s390"><title>Purchasing Hardware Specifically for GNU/Linux</title>
51
52	<para>
53
54	There are several vendors, who ship systems with Debian or other
55	distributions of GNU/Linux pre-installed. You might pay more for the
56	privilege, but it does buy a level of peace of mind, since you can be
57	sure that the hardware is well-supported by GNU/Linux.
58
59	</para><para arch="m68k">
60
61	Unfortunately, it's quite rare to find any vendor shipping
62	new &arch-title; machines at all.
63
64	</para><para arch="i386">
65
66	If you do have to buy a machine with Windows bundled, carefully read
67	the software license that comes with Windows; you may be able to
68	reject the license and obtain a rebate from your vendor. See
69	<ulink url="&url-windows-refund;"></ulink> for complete details.
70
71	</para><para>
72
73	Whether or not you are purchasing a system with Linux bundled, or even
74	a used system, it is still important to check that your hardware is
75	supported by the Linux kernel. Check if your hardware is listed in
76	the references found above. Let your salesperson (if any) know that
77	you're shopping for a Linux system. Support Linux-friendly hardware
78	vendors.
79
80	</para>
81
82	<sect2><title>Avoid Proprietary or Closed Hardware</title>
83	<para>
84
85	Some hardware manufacturers simply won't tell us how to write drivers
86	for their hardware. Others won't allow us access to the documentation
87	without a non-disclosure agreement that would prevent us from
88	releasing the Linux source code.
89
90	</para><para arch="m68k">
91
92	Another example is the proprietary hardware in the older
93	Macintosh line. In fact, no specifications or documentation have ever
94	been released for any Macintosh hardware, most notably the ADB
95	controller (used by the mouse and keyboard), the floppy controller,
96	and all acceleration and CLUT manipulation of the video hardware
97	(though we do now support CLUT manipulation on nearly all internal
98	video chips). In a nutshell, this explains why the Macintosh Linux
99	port lags behind other Linux ports.
100
101	</para><para>
102
103	Since we haven't been granted access to the documentation on these
104	devices, they simply won't work under Linux. You can help by asking
105	the manufacturers of such hardware to release the documentation. If
106	enough people ask, they will realize that the free software community
107	is an important market.
108
109	</para>
110	</sect2>
111
112
113	<sect2 arch="i386"><title>Windows-specific Hardware</title>
114	<para>
115
116	A disturbing trend is the proliferation of Windows-specific modems and
117	printers. In some cases these are specially designed to be operated by
118	the Microsoft Windows operating system and bear the legend
119	``WinModem'' or ``Made especially for Windows-based computers''. This
120	is generally done by removing the embedded processors of the hardware
121	and shifting the work they do over to a Windows driver that is run by
122	your computer's main CPU. This strategy makes the hardware less
123	expensive, but the savings are often <emphasis>not</emphasis> passed on to the
124	user and this hardware may even be more expensive than equivalent
125	devices that retain their embedded intelligence.
126
127	</para><para>
128
129	You should avoid Windows-specific hardware for two reasons. The first
130	is that the manufacturers do not generally make the resources
131	available to write a Linux driver. Generally, the hardware and
132	software interface to the device is proprietary, and documentation is
133	not available without a non-disclosure agreement, if it is available
134	at all. This precludes its being used for free software, since free
135	software writers disclose the source code of their programs. The
136	second reason is that when devices like these have had their embedded
137	processors removed, the operating system must perform the work of the
138	embedded processors, often at <emphasis>real-time</emphasis> priority,
139	and thus the CPU is not available to run your programs while it is
140	driving these devices. Since the typical Windows user does not
141	multi-process as intensively as a Linux user, the manufacturers hope
142	that the Windows user simply won't notice the burden this hardware
143	places on their CPU. However, any multi-processing operating system,
144	even Windows 95 or NT, suffers from degraded performance when
145	peripheral manufacturers skimp on the embedded processing power of
146	their hardware.
147
148	</para><para>
149
150	You can help this situation by encouraging these manufacturers to
151	release the documentation and other resources necessary for us to
152	program their hardware, but the best strategy is simply to avoid this
153	sort of hardware until it is listed as working in the
154	<ulink url="&url-hardware-howto;">Linux Hardware Compatibility HOWTO</ulink>.
155
156	</para>
157	</sect2>
158
159
160	<sect2 id="Parity-RAM"><title>Fake or ``Virtual'' Parity RAM</title>
161	<para>
162
163	If you ask for Parity RAM in a computer store, you'll probably get
164	<emphasis>virtual parity</emphasis> memory modules instead of
165	<emphasis>true parity</emphasis> ones. Virtual parity SIMMs can often
166	(but not always) be distinguished because they only have one more chip
167	than an equivalent non-parity SIMM, and that one extra chip is smaller
168	than all the others. Virtual-parity SIMMs work exactly like non-parity
169	memory. They can't tell you when you have a single-bit RAM error the
170	way true-parity SIMMs do in a motherboard that implements
171	parity. Don't ever pay more for a virtual-parity SIMM than a
172	non-parity one. Do expect to pay a little more for true-parity SIMMs,
173	because you are actually buying one extra bit of memory for every 8
174	bits.
175
176	</para><para>
177
178	If you want complete information on &arch-title; RAM issues, and what
179	is the best RAM to buy, see the
180	<ulink url="&url-pc-hw-faq;">PC Hardware FAQ</ulink>.
181
182	</para><para arch="alpha">
183
184	Most, if not all, Alpha systems require true-parity RAM.
185
186	</para>
187
188	</sect2>
189
190	</sect1>