This section will walk you through pre-installation hardware setup, if any, that you will need to do prior to installing Debian. Generally, this involves checking and possibly changing firmware settings for your system. The firmware is the core software used by the hardware; it is most critically invoked during the bootstrap process (after power-up). Known hardware issues affecting the reliability of &debian; on your system are also highlighted. &bios-setup-i386.xml; &bios-setup-m68k.xml; &bios-setup-powerpc.xml; &bios-setup-sparc.xml; &bios-setup-s390.xml; Many people have tried operating their 90 MHz CPU at 100 MHz, etc. It sometimes works, but is sensitive to temperature and other factors and can actually damage your system. One of the authors of this document over-clocked his own system for a year, and then the system started aborting the gcc program with an unexpected signal while it was compiling the operating system kernel. Turning the CPU speed back down to its rated value solved the problem. The gcc compiler is often the first thing to die from bad memory modules (or other hardware problems that change data unpredictably) because it builds huge data structures that it traverses repeatedly. An error in these data structures will cause it to execute an illegal instruction or access a non-existent address. The symptom of this will be gcc dying from an unexpected signal. Atari TT RAM boards are notorious for RAM problems under Linux; if you encounter any strange problems, try running at least the kernel in ST-RAM. Amiga users may need to exclude RAM using a booter memfile. FIXME: more description of this needed. If you do have true-parity RAM and your motherboard can handle it, be sure to enable any BIOS settings that cause the motherboard to interrupt on memory parity errors. Many systems have a turbo switch that controls the speed of the CPU. Select the high-speed setting. If your BIOS allows you to disable software control of the turbo switch (or software control of CPU speed), do so and lock the system in high-speed mode. We have one report that on a particular system, while Linux is auto-probing (looking for hardware devices) it can accidentally touch the software control for the turbo switch. Many users of Cyrix CPUs have had to disable the cache in their systems during installation, because the floppy disk has errors if they do not. If you have to do this, be sure to re-enable your cache when you are finished with installation, as the system runs much slower with the cache disabled. We don't think this is necessarily the fault of the Cyrix CPU. It may be something that Linux can work around. We'll continue to look into the problem. For the technically curious, we suspect a problem with the cache being invalid after a switch from 16-bit to 32-bit code. You may have to change some settings or jumpers on your computer's peripheral cards. Some cards have setup menus, while others rely on jumpers. This document cannot hope to provide complete information on every hardware device; what it hopes to provide is useful tips. If any cards provide mapped memory, the memory should be mapped somewhere between 0xA0000 and 0xFFFFF (from 640K to just below 1 megabyte) or at an address at least 1 megabyte greater than the total amount of RAM in your system. If you have no AT-style keyboard and only a USB model, you may need to enable legacy AT keyboard emulation in your BIOS setup. Only do this if the installation system fails to use your keyboard in USB mode. Conversely, for some systems (especially laptops) you may need to disable legacy USB support if your keyboard does not respond. Consult your main board manual and look in the BIOS for Legacy keyboard emulation or USB keyboard support options. The Linux Kernel cannot always detect what amount of RAM you have. If this is the case please look at . Some OldWorld Powermacs, most notably those with the control display driver, may not reliable produce a colormap under Linux when the display is configured for more than 256 colors. If you are experiencing such issues with your display after rebooting (you can sometimes see data on the monitor, but on other occasions cannot see anything) or, if the screen turns black after booting the installer instead of showing you the user interface, try changing your display settings under MacOS to use 256 colors instead of thousands or millions.