ca/hardware/supported-peripherals.xml

<!-- retain these comments for translator revision tracking -->
<!-- $Id: supported-peripherals.xml,v 1.4 2003/06/15 17:45:10 toff 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.

<![ %i386; [
USB keyboards may require additional configuration 
(see <xref linkend="usb-keyboard-config"></xref>).
]]>

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

</para>

<![ %i386; [
<para>

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>

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>

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"></xref>).

</para>
]]>

<![ %s390; [
<para>

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>
]]>

<![ %not-s390; [

 <sect1><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.  

<![ %m68k; [ Unfortunately, it's quite rare to find any vendor shipping
new &arch-title; machines at all. ]]>

<![ %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>

<![ %m68k; [ 
<para>

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>

<![ %i386; [

  <sect2><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>

<!-- end %i386; --> ]]>

  <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>

<![ %alpha; [ 
<para>

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

</para>
]]>
  </sect2>

<!-- end %not-s390; --> ]]>

 </sect1>
1	<!-- retain these comments for translator revision tracking -->
2	<!-- $Id: supported-peripherals.xml,v 1.4 2003/06/15 17:45:10 toff 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	<![ %i386; [
13	USB keyboards may require additional configuration
14	(see <xref linkend="usb-keyboard-config"></xref>).
15	]]>
16
17	This section contains information about peripherals specifically
18	<emphasis>not</emphasis> supported by the installation system, even
19	though they may be supported by Linux.
20
21	</para>
22
23	<![ %i386; [
24	<para>
25
26	Again, see the
27	<ulink url="&url-hardware-howto;">Linux Hardware Compatibility HOWTO"></ulink>
28	to determine whether your specific hardware is supported by Linux.
29
30	</para><para>
31
32	USB hardware is supported by the flavor "bf2.4". If you find that you
33	cannot use some USB devices, you may upgrade to kernel 2.4.x later.
34
35	</para><para>
36
37	Note that the stock kernels do not support serial ports numbered
38	greater than four (<filename>/dev/ttyS3</filename>). You'll have to
39	either use the available ports, or else build a custom kernel (see
40	<xref linkend="rescue-replace-kernel"></xref>).
41
42	</para>
43	]]>
44
45	<![ %s390; [
46	<para>
47
48	Package installations from XPRAM and tape are not supported by this
49	system. All packages that you want to install need to be available on a
50	DASD or over the network using NFS, HTTP or FTP.
51
52	</para>
53	]]>
54
55	<![ %not-s390; [
56
57	<sect1><title>Purchasing Hardware Specifically for GNU/Linux</title>
58
59	<para>
60
61	There are several vendors, who ship systems with Debian or other
62	distributions of GNU/Linux pre-installed. You might pay more for the
63	privilege, but it does buy a level of peace of mind, since you can be
64	sure that the hardware is well-supported by GNU/Linux.
65
66	<![ %m68k; [ Unfortunately, it's quite rare to find any vendor shipping
67	new &arch-title; machines at all. ]]>
68
69	<![ %i386; [ If you do have to buy a
70	machine with Windows bundled, carefully read the software license that
71	comes with Windows; you may be able to reject the license and obtain a
72	rebate from your vendor. See
73	<ulink url="&url-windows-refund;"></ulink>
74	for complete details. ]]>
75
76	</para><para>
77
78	Whether or not you are purchasing a system with Linux bundled, or even
79	a used system, it is still important to check that your hardware is
80	supported by the Linux kernel. Check if your hardware is listed in
81	the references found above. Let your salesperson (if any) know that
82	you're shopping for a Linux system. Support Linux-friendly hardware
83	vendors.
84
85	</para>
86
87	<sect2><title>Avoid Proprietary or Closed Hardware</title>
88	<para>
89
90	Some hardware manufacturers simply won't tell us how to write drivers
91	for their hardware. Others won't allow us access to the documentation
92	without a non-disclosure agreement that would prevent us from
93	releasing the Linux source code.
94
95	</para>
96
97	<![ %m68k; [
98	<para>
99
100	Another example is the proprietary hardware in the older
101	Macintosh line. In fact, no specifications or documentation have ever
102	been released for any Macintosh hardware, most notably the ADB
103	controller (used by the mouse and keyboard), the floppy controller,
104	and all acceleration and CLUT manipulation of the video hardware
105	(though we do now support CLUT manipulation on nearly all internal
106	video chips). In a nutshell, this explains why the Macintosh Linux
107	port lags behind other Linux ports.
108
109	</para>
110	]]>
111
112	<para>
113
114	Since we haven't been granted access to the documentation on these
115	devices, they simply won't work under Linux. You can help by asking
116	the manufacturers of such hardware to release the documentation. If
117	enough people ask, they will realize that the free software community
118	is an important market.
119
120	</para>
121	</sect2>
122
123	<![ %i386; [
124
125	<sect2><title>Windows-specific Hardware</title>
126	<para>
127
128	A disturbing trend is the proliferation of Windows-specific modems and
129	printers. In some cases these are specially designed to be operated by
130	the Microsoft Windows operating system and bear the legend
131	``WinModem'' or ``Made especially for Windows-based computers''. This
132	is generally done by removing the embedded processors of the hardware
133	and shifting the work they do over to a Windows driver that is run by
134	your computer's main CPU. This strategy makes the hardware less
135	expensive, but the savings are often <emphasis>not</emphasis> passed on to the
136	user and this hardware may even be more expensive than equivalent
137	devices that retain their embedded intelligence.
138
139	</para><para>
140
141	You should avoid Windows-specific hardware for two reasons. The first
142	is that the manufacturers do not generally make the resources
143	available to write a Linux driver. Generally, the hardware and
144	software interface to the device is proprietary, and documentation is
145	not available without a non-disclosure agreement, if it is available
146	at all. This precludes its being used for free software, since free
147	software writers disclose the source code of their programs. The
148	second reason is that when devices like these have had their embedded
149	processors removed, the operating system must perform the work of the
150	embedded processors, often at <emphasis>real-time</emphasis> priority,
151	and thus the CPU is not available to run your programs while it is
152	driving these devices. Since the typical Windows user does not
153	multi-process as intensively as a Linux user, the manufacturers hope
154	that the Windows user simply won't notice the burden this hardware
155	places on their CPU. However, any multi-processing operating system,
156	even Windows 95 or NT, suffers from degraded performance when
157	peripheral manufacturers skimp on the embedded processing power of
158	their hardware.
159
160	</para><para>
161
162	You can help this situation by encouraging these manufacturers to
163	release the documentation and other resources necessary for us to
164	program their hardware, but the best strategy is simply to avoid this
165	sort of hardware until it is listed as working in the
166	<ulink url="&url-hardware-howto;">Linux Hardware Compatibility HOWTO</ulink>.
167
168	</para>
169	</sect2>
170
171	<!-- end %i386; --> ]]>
172
173	<sect2 id="Parity-RAM"><title>Fake or ``Virtual'' Parity RAM</title>
174	<para>
175
176	If you ask for Parity RAM in a computer store, you'll probably get
177	<emphasis>virtual parity</emphasis> memory modules instead of
178	<emphasis>true parity</emphasis> ones. Virtual parity SIMMs can often
179	(but not always) be distinguished because they only have one more chip
180	than an equivalent non-parity SIMM, and that one extra chip is smaller
181	than all the others. Virtual-parity SIMMs work exactly like non-parity
182	memory. They can't tell you when you have a single-bit RAM error the
183	way true-parity SIMMs do in a motherboard that implements
184	parity. Don't ever pay more for a virtual-parity SIMM than a
185	non-parity one. Do expect to pay a little more for true-parity SIMMs,
186	because you are actually buying one extra bit of memory for every 8
187	bits.
188
189	</para><para>
190
191	If you want complete information on &arch-title; RAM issues, and what
192	is the best RAM to buy, see the
193	<ulink url="&url-pc-hw-faq;">PC Hardware FAQ></ulink>.
194
195	</para>
196
197	<![ %alpha; [
198	<para>
199
200	Most, if not all, Alpha systems require true-parity RAM.
201
202	</para>
203	]]>
204	</sect2>
205
206	<!-- end %not-s390; --> ]]>
207
208	</sect1>