The AMI BIOS Survival Guide
Edited by Jean-Paul Rodrigue
Gordon L. Burditt (firstname.lastname@example.org)
Peter Herweijer (email@example.com)
Kajetan Hinner (firstname.lastname@example.org)
Piotr Karocki (email@example.com)
Brian Lee (firstname.lastname@example.org)
Aad Offerman (email@example.com)
Keith Rohrer (firstname.lastname@example.org)
Jerome Schneider (email@example.com)
Cameron Spitzer (firstname.lastname@example.org)
Andy Walton (email@example.com)
Version 1.0 to 1.3: December 1993 (initial postings)
Version 2.0 to 2.4: January 1994 (the first "complete" versions)
Version 2.5 and 2.6 : February 1994 (vitamin C added)
Version 2.65 and 2.7: March 1994 (no cholesterol)
Version 3.0: 16-04-94 (new prune-strawberry-cabbage flavour)
Version 3.1: 13-05-94 (friday the 13th edition)
What's new in version 3.1 (*)
- FTP archive site available for the guide.
- A list of BIOS error messages (see section 2.4)
- Several additions to various topics (*).
comp.sys.ibm.pc.hardware.misc & comp.answers (patent pending).
(*) Archive Site
The guide, along with other hardware-related FAQs, is available through
anonymous FTP at rahul.net in the pub/cameron/PC-info directory. The
document is compressed by Gzip, available at any GNU archive sites like
gatekeeper.dec.com, in the pub/GNU directory.
What is the AMI BIOS survival guide?
BIOS settings are a frequent problem in several hardware related
newsgroups. Did you ever experienced a system lock up or poor
performance and erratic behaviour due to improper BIOS settings? Have
you ever been let in the dark by a cryptic 5 pages badly written
motherboard manual? The answer is probably yes. I took some initiative
and decided to edit a FAQ for the AMI BIOS (American Megatrends
Inc.). This BIOS is, I believe, the most common. The guide provides a
description of each BIOS functions (at least those we are aware of) and
tips for their settings. I hope it will eventually help newbies "decipher"
BIOS settings and more advanced users "optimize" their system. It could
even keep you from a painful visit to your local computer store!
Disclaimer and other stuff
This document is provided "as is". The editor and contributors take no
responsabilities for any problems, damages, humiliations, world wars or
loss of sanity resulting from improper BIOS settings. If you are in doubt,
please post a question to the comp.sys.ibm.pc.hardware.chips newsgroup
or refer to a competent computer technician. Messing up with something
you do not understand will often get you in trouble (Who doesn't know
someone who did?). YOU HAVE BEEN WARNED.
This guide is provided as a free reference for the usenet (internet)
community. You may distribute it freely as long as the contents are not
altered, no fees are asked, and references to the editor and contributors
are kept. If you are making money out of this file or posting net-wide (to
groups where it does not belong) religious babblings or green card lottery
scam: may your CPU perish by electromigration!
I want to know more...
If you have an UNSOLVED BIOS problem not described herein, please
post it to related newsgroups (like comp.sys.ibm.pc.hardware.chips),
NOT to the editor or the contributors. You should also have a look at the
ibm.pc.hardware.* Frequently Asked Questions (FTP rtfm.mit.edu;
directory: /pub/usenet/news.answers/csiph-faq; filenames: part1 to part5)
posted regularly. It contains a wealth of information about computer
hardware. Look also in the comp.answers newsgroup for available FAQs.
If you have a SOLVED problem, please send it to the editor so it can be
added to subsequent versions of this document. Your contributions or
comments will be much appreciated. If you want the most recent version
of this document, please e-mail the editor and tell what version you
currently have. If a more recent version is available, it will be fowarded.
Before doing so, please look in this newsgroup for a regular posting of this
If you want various technical information about AMI BIOS, you can find
it at the FTP site AMERICAN.MEGATRENDS.COM. If you can afford
long distance charges, try the AMI BBS at (404) 246-8780 (or 8781, 8782,
8783). There is also a shareware named AMISETUP that enables BIOS
settings and provides an on-line reference (for registered versions). It can
even let you access some settings that could not be accessed otherwise.
You can find it at SIMTEL mirror sites like FTP.WUSTL.EDU or
OAK.OAKLAND.EDU in the /systems/ibmpc/msdos/sysutil directory.
The file name is AMISE260.ZIP.
One last thing...
I would like to thank the contributors to have taken some of their time to
write varied topics and provide enlightening feedbacks. Some parts of this
document are still incomplete and some information may be inaccurate.
Your feedbacks will help this document be as accurate and up to date as
possible. I am sorry if I cannot answer to everyone or add everything that
is send to me.
I would also like to thank the following persons for providing information
on specific topics: Michiel de Vries, Andy Eskilsson, Doug Hogarth,
Reinhard Kirchner, Mirek Komon, Jim Kozma, Juha Laiho, Alain Lavoie,
Erik Mouw, Chris Pollard, Dietrich Schmidt, Hans Schrader, Loren
Schwiebert, Dan Sobel, Dave Spensley and Dmitry Stefankov.
TABLE OF CONTENT
2.0 POST AND ENTERING SETUP
2.1 A Typical AMI BIOS POST Sequence
2.2 AMI BIOS POST Errors
2.3 Other AMI BIOS POST Codes
(*) 2.4 BIOS Error Messages
3.0 STANDARD CMOS SETUP
4.0 ADVANCED CMOS SETUP
5.0 ADVANCED CHIPSET SETUP
6.0 AUTO CONFIGURATION WITH BIOS DEFAULTS
7.0 AUTO CONFIGURATION WITH POWER-ON DEFAULTS
8.0 CHANGE PASSWORD
9.0 HARD DISK UTILITY
9.1 Hard Disk Format
9.2 Auto Detect Hard Disk
9.3 Auto Interleave
9.4 Media Analysis.
10.0 WRITE TO CMOS AND EXIT
11.0 DO NOT WRITE TO CMOS AND EXIT
12.0 FREQUENTLY ASKED QUESTIONS (FAQ)
1.1 BIOS: Basic Input Output System. Computer hardware has to work
with software, so it needs an interface with it. The BIOS gives the
computer a little built-in starter kit to run the rest of softwares from floppy
disks (FDD) and hard disks (HDD). The BIOS is responsible for booting
the computer by providing a basic set of instructions. It performs all the
tasks that need to be done at start-up time: POST (Power-On Self Test,
booting an operating system from FDD or HDD). Furthermore, it
provides an interface to the underlying hardware for the operating system
in the form of a library of interrupt handlers. For instance, each time a
key is pressed, the CPU (Central Processing Unit) perform an interrupt to
read that key. This is similar for other input/output devices (Serial and
parallel ports, video cards, sound cards, hard disk controllers, etc...).
Some older PC's cannot co-operate with all the modern hardware because
their BIOS doesn't support that hardware. The operating system cannot
call a BIOS routine to use it; this problem can be solved by replacing your
BIOS with an newer one, that does support your new hardware, or by
installing a device driver for the hardware.
1.2 CMOS: Complementary Metal Oxide Semiconductor. To perform its
tasks, the BIOS need to know various parameters (hardware
configuration). These are permanently saved in a little piece (64 bytes) of
CMOS RAM (short: CMOS). The CMOS power is supplied by a little
battery, so its contents will not be lost after the PC is turned off.
Therefore, there is a battery and a small RAM memory on board, which
never (should...) loses its information. The memory was in earlier times
a part of the clock chip, now it's part of such a highly Integrated Circuit
(IC). CMOS is the name of a technology which needs very low power,
so the computer's battery is not too much in use. Actually there is not a
battery on new boards, but an accumulator (Ni_Cad in most cases). It is
recharged every time the computer is turned on. If your CMOS is
powered by external batteries, be sure that they are in good operating
condition. Also, be sure that they do not leak. It may damage the
motherboard. Otherwise, your CMOS may suddenly "forget" its
configuration and you may be looking for a problem elsewhere. In the
monolithic PC and PC/XT this information is supplied by setting the DIP
(Dual-In-line Package) switches at the motherboard or peripheral cards.
Some new motherboards have a technology named the Dallas Nov-Ram.
It eliminates having an on-board battery: There is a 10 year lithium cell
epoxyed into the chip.
1.3 Chipset: A PC consists of different functional parts on its
motherboard: ISA (Industry Standard Architecture), EISA (Enhanced
Industry Standard Architecture) VESA (Video Enhanced Standards
Association) and PCI (Peripheral Component Interface) slots, memory,
cache memory, keyboard plug etc... The chipset enables a set of
instructions so the CPU can work (communicate) with other parts of the
motherboard. Nowadays most of the discrete chips; PIC (Programmable
Interrupt Controller), DMA (Direct Memory Access), MMU (Memory
Management Unit), cache, etc... are packed together on one, two or three
chips; the chipset. SETUP allows you to change the parameters with
which the BIOS configures your chipset. Since chipsets of a different
brand are not the same, for every chipset there is a BIOS version. Now
we have fewer and fewer chipsets which do the job. Some chipsets have
more features, some less. OPTi is such a commonly used chipset. In
some well integrated motherboards, the only components present are the
CPU, the two BIOS chips (BIOS and Keyboard BIOS), one chipset IC,
cache memory (DRAMs, Dynamic Random Access Memory), memory
(SIMMs, Single Inline Memory Module, most of the time) and a clock
2.0 POST AND ENTERING SETUP
When the system is powered on, the BIOS will perform diagnostics and
initialize system components, including the video system. (This is
self-evident when the screen first flicks before the Video Card header is
displayed). This is commonly refered as POST (Power-On Self Test).
Afterwards, the computer will proceed its final boot-up stage by calling
the operating system. Just before that, the user may interupt to have access
To allow the user to alter the CMOS settings, the BIOS provides a little
program, SETUP. Mostly setup can be entered by pressing a special key
combination (DEL, ESC, CTRL-ESC, or CRTL-ALT-ESC) at boot time
(Some BIOSes allow you to enter setup at any time by pressing
CTRL-ALT-ESC). The AMI BIOS is mostly entered by pressing the DEL
key after resetting (CTRL-ALT-DEL) or powering up the computer. You
can bypass the extended CMOS settings by holding the
Note: I (firstname.lastname@example.org) did not write this survival guide. Refer to the
contributors or the editor (or post your question to usenet) if you have
any questions. Thanks..
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