21
21
&bios-setup-sparc.xml;
22
22
&bios-setup-s390.xml;
24
<sect2><title>Hardware Issues to Watch Out For</title>
25
<para arch="not-s390">
27
Many people have tried operating their 90 MHz CPU at 100 MHz, etc. It
28
sometimes works, but is sensitive to temperature and other factors and
29
can actually damage your system. One of the authors of this document
30
over-clocked his own system for a year, and then the system started
31
aborting the <command>gcc</command> program with an unexpected signal
32
while it was compiling the operating system kernel. Turning the CPU
33
speed back down to its rated value solved the problem.
35
</para><para arch="not-s390">
37
The <command>gcc</command> compiler is often the first thing to die
38
from bad memory modules (or other hardware problems that change data
39
unpredictably) because it builds huge data structures that it
40
traverses repeatedly. An error in these data structures will cause it
41
to execute an illegal instruction or access a non-existent
42
address. The symptom of this will be <command>gcc</command> dying from
45
</para><para arch="m68k">
24
<sect2 arch="m68k;x86;powerpc" id="hardware-issues">
25
<title>Hardware Issues to Watch Out For</title>
47
29
Atari TT RAM boards are notorious for RAM problems under Linux; if you
48
30
encounter any strange problems, try running at least the kernel in
55
37
</emphasis></phrase>
57
</para><para arch="i386">
59
The very best motherboards support parity RAM and will actually tell
60
you if your system has a single-bit error in RAM. Unfortunately, they
61
don't have a way to fix the error, thus they generally crash
62
immediately after they tell you about the bad RAM. Still, it's better
63
to be told you have bad memory than to have it silently insert errors
64
in your data. Thus, the best systems have motherboards that support
65
parity and true-parity memory modules; see
66
<xref linkend="Parity-RAM"/>.
68
</para><para arch="i386">
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If you do have true-parity RAM and your motherboard can handle it, be
71
sure to enable any BIOS settings that cause the motherboard to
72
interrupt on memory parity errors.
76
<sect3 arch="i386"><title>The Turbo Switch</title>
79
Many systems have a <emphasis>turbo</emphasis> switch that controls
80
the speed of the CPU. Select the high-speed setting. If your BIOS
81
allows you to disable software control of the turbo switch (or
82
software control of CPU speed), do so and lock the system in
83
high-speed mode. We have one report that on a particular system, while
84
Linux is auto-probing (looking for hardware devices) it can
85
accidentally touch the software control for the turbo switch.
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<sect3 arch="i386"><title>Cyrix CPUs and Floppy Disk Errors</title>
93
Many users of Cyrix CPUs have had to disable the cache in their
94
systems during installation, because the floppy disk has errors if
95
they do not. If you have to do this, be sure to re-enable your cache
96
when you are finished with installation, as the system runs
97
<emphasis>much</emphasis> slower with the cache disabled.
101
We don't think this is necessarily the fault of the Cyrix CPU. It may
102
be something that Linux can work around. We'll continue to look into
103
the problem. For the technically curious, we suspect a problem with
104
the cache being invalid after a switch from 16-bit to 32-bit code.
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<sect3 arch="i386"><title>Peripheral Hardware Settings</title>
112
You may have to change some settings or jumpers on your computer's
113
peripheral cards. Some cards have setup menus, while others rely on
114
jumpers. This document cannot hope to provide complete information on
115
every hardware device; what it hopes to provide is useful tips.
119
If any cards provide <quote>mapped memory</quote>, the memory should be
120
mapped somewhere between 0xA0000 and 0xFFFFF (from 640K to just below 1
121
megabyte) or at an address at least 1 megabyte greater than the total
122
amount of RAM in your system.
127
<sect3 arch="i386" id="usb-keyboard-config">
41
<formalpara arch="x86">
128
42
<title>USB BIOS support and keyboards</title>
137
51
keyboard emulation</quote> or <quote>USB keyboard support</quote> options.
142
<sect3><title>More than 64 MB RAM</title>
145
The Linux Kernel cannot always detect what amount of RAM you have. If
146
this is the case please look at <xref linkend="boot-parms"/>.
151
<sect3 arch="powerpc">
152
<title>Display visibility on OldWorld Powermacs</title>
56
<formalpara arch="powerpc">
57
<title>Display-visibility on OldWorld Powermacs</title>
155
60
Some OldWorld Powermacs, most notably those with the <quote>control</quote>
156
display driver but possibly others as well, may not produce a colormap with
157
reliably results in visible output under Linux when the display is
158
configured for more than 256 colors. If you are experiencing such issues
159
with your display after rebooting (you can sometimes see data on
61
display driver, may not reliably produce a colormap under Linux when the
62
display is configured for more than 256 colors. If you are experiencing such
63
issues with your display after rebooting (you can sometimes see data on
160
64
the monitor, but on other occasions cannot see anything) or, if the screen
161
65
turns black after booting the installer instead of showing you the user
162
66
interface, try changing your display settings under MacOS to use 256
163
67
colors instead of <quote>thousands</quote> or <quote>millions</quote>.