AMIBIOS

AMIBIOS is a Personal Computer BIOS developed by AMI (American Megatrends), which bought off it's rights from Access Methods Inc. in around 1986. Earliest known release of AMIBIOS is from 1985. While AMIBIOS is still in use on some industrial legacy machines to this day, it is no longer in use for most personal computers since early-2010s due to UEFI's increasing popularity. AMIBIOS has been mostly replaced by Aptio, the EFI/UEFI firmware developed by AMI.

Purchase from Access Methods

Main page: American Megatrends

Access Methods Inc. created AMIBIOS in 1985. Same year, Access Methods' owners (Subramonian Shankar and Pat Sarma) found a new company from the funds of Access Methods, called Quintessential Consultants Inc. (QCI). It then got renamed to American Megatrends Inc. (AMI) to keep the "AMIBIOS" acronym. American Megatrends then bought AMIBIOS from Access Methods in 1986.

List of known versions

All versions made before AMIBIOS Plus were first released by Access Methods, although some later cores of these versions (ones released after the purchase) had American Megatrends copyright as the updated cores were released by them.

Versions from AMIBIOS 2.2x all the way to AMIBIOS 6 and AMIBIOS 07.00.10 can often be identified by their subcore dates, which actually does not change depending on the BIOS compile date (unlike other AMIBIOS 07.00.xx releases and AMIBIOS 8) and were fixed dates from AMI indicating the subcore release date. The subcore date can be found in the BIOS string during POST (refer to the BIOS string section of this page for further information). Please note that the core dates were occasionally modified by OEMs or motherboard manufacturers, especially during the pre-WinBIOS (AMIBIOS 4) era. Full list of subcores are available on the main page for each of these BIOS versions.

Notice: Core version labelling for very early AMIBIOS versions (pre-AMIBIOS Plus) is unknown due to lack of photos, ROM files and documents. As more information is available, these will be corrected.

List of known AMIBIOS versions

Main core version	Main core release date	Earliest known subcore date	Last known subcore date	POST screen	Notes
"Rev-X2-03" (Actual core version unknown)	1985 or 1986(?)	No subcore dates used	No subcore dates used		Possibly earliest known version.
AMIBIOS 2.2x(?)	1986	061286 (June 12, 1986)	013189 (January 31, 1989)		Assumed to be AMIBIOS 2.2x, might not be correct.
AMI Plus BIOS	1987	110387 (November 3, 1987)	030891 (March 8, 1991)
AMI Hi-Flex BIOS	1990	111590 (November 15, 1990)	011094 (January 10, 1994)		Programmer's guide to AMIBIOS book does not list releases with core dates before 031591 (March 15, 1991) as Hi-Flex, however earlier core dates do definitely exist. Not to be confused with the Hi-Flex Setup Utility on AMIBIOS 6 and 07.00.10 (although the setup utility was named after it). Hi-Flex might also be AMIBIOS 3.
AMI WinBIOS (AMIBIOS 4)	1993	121593 (December 15, 1993)	081594 (August 15, 1994)		Often referred to as AMI WinBIOS, not to be confused with the WinBIOS Setup Utility on AMIBIOS 5 and 6 (although that was named after it). Subcore 082594 also exists, although it's assumed to be a re-badge of subcore 072594 modified by some OEMs due to lower core version compared to 081594.
AMIBIOS 5	1994	101094 (October 10, 1994)	None (101094 only)
AMIBIOS 6	1995	071595 (July 15, 1995)	071599 (July 15, 1999)
AMIBIOS 07.00.xx	1999	No subcore dates used	No subcore dates used	Not to be confused with AMIBIOS 7 (07.00.10, subcore date 040201)
AMIBIOS 7 (07.00.10)	2001	040201 (April 2, 2001)	None (040201 only)	Not to be confused with AMIBIOS 07.00.xx
AMIBIOS 8	2001	No subcore dates used	No subcore dates used	Last version of AMIBIOS

BIOS string

The BIOS string for AMIBIOS was first introduced with AMIBIOS 2.2x for easy identification of each BIOS release and is often seen during POST at the very bottom of the screen. The string format was changed a couple times with new core versions of AMIBIOS. Known codes for some identification sections are given in the List of codes for BIOS strings section.

AMIBIOS 2.2x

MMMM: Manufacturer/OEM identification code, SSSSSS: BIOS subcore release date

MMMM-SSSSSS

Example string: 1406-061286

This string is for a 06/12/86 (June 12, 1986; date is in American format) dated subcore BIOS for Flying Triumph Co. Ltd. ("1406").

AMI Plus BIOS

D: CMOS setup type, CCC: Chipset type, MMMM: Manufacturer/OEM identification code, SSSSSS: BIOS subcore release date, KK: Keyboard controller (KBC) ID (with second character indicating the model).

DCCC-MMMM-SSSSSS-KK

Note: The CMOS setup type code can be two characters for "DE" in case the BIOS contains both extended setup and built-in diagnostics.

Example string: D286-1277-043089-K0

This string is for a 04/30/89 (April 30, 1989; date is in American format) dated subcore AMI Plus BIOS with regular CMOS setup and built-in diagnostics ("D") for a machine with a discrete i286 logic ("286") and a default/unknown keyboard controller (K"0") made by Trangg Bow Co. ("1277").

Later BIOS versions

C: Processor architecture, R: ROM size, MMMM: Manufacturer/OEM identification code, FFFFFFFF: BIOS feature identification (often 00101111), SSSSSS: BIOS compile date OR subcore release date, DDDDDDDD: BIOS identifier, Project: BIOS project ID (no maximum characters), K: Keyboard controller (KBC) ID

CR-VVVV-00MMMM-FFFFFFFF-SSSSSS-DDDDDDDD-Project-K

Note: The project ID section is only present on late AMIBIOS 6 and later releases. The keyboard controller ID is also not used since AMIBIOS 07.00.xx.

Example string: 61-1108-001169-00101111-071595-440BX/ZX-1440B000-H

This string is for a 11.08 revision ("1108") 128 KB ("1") size AMIBIOS 6 ("071595", main subcore for it) for a motherboard for 686 architecture processors ("6") with Intel 440BX or 440ZX chipset ("440BX/ZX") and an AMIKEY-2 clone keyboard controller ("H") made by MSI ("1169").

List of known codes for BIOS strings

Click "Expand" to view.

AMI Plus BIOS CMOS setup type codes:
D 	CMOS Setup & Built-in Diagnostics
E 	Extended CMOS Setup
S 	Regular CMOS Setup
DE	Extended CMOS Setup & Built-in Diagnostics

AMI Plus BIOS Chipset codes:
C&T 	Chips & Technologies C&T 386 chipset
NET 	Chips & Technologies NEAT chipset
286 	VLSI or G2 286 chipset, or discrete 286 logic
SUN 	SUNTAC chipset
PAQ 	COMPAQ Portable or ZyMOS POACH chipset
AMI 	AMI 386 motherboards
G23 	G23 chipset

AMIBIOS ROM size codes
0	64KB
1	128KB/1MB/2MB
2	256KB
3	512KB
4	1MB
5	2MB
6	4MB
7	8MB
8	16MB
9	32MB

AMIBIOS CPU architecture codes
2	286
3	386
4	486
5	586
6	686

AMIBIOS manufacturer codes:
0394 	Sukjung
1101 	Sunlogix Inc
1102 	Soyo
1103 	Tidalpower Technology Inc
1105 	Autocomputer Co
1106 	Dynasty Computer Inc
1107 	Dataexpert
1108 	Chaplet
1109 	Fair Friend Ent. Co
1111 	Paoku P&C Co
1112 	Aquarius Systems Inc
1113 	Micro Leader Enterprises
1114 	Iwill
1115 	Senor Science Co
1116 	Chicony
1117 	Atrend
1120 	Unicorn
1121 	FIC (FICA)
1122 	Microstar (MSI)
1123 	Magtron Technology Co
1124 	Tekram
1126 	Chuntex Elex
1128 	Chaintech
1130 	Pai Jung Electronic Ind
1131 	ECS (Elitegroup)
1131 	PC Chips (Hsin Tech)
1132 	Dkine Enterprise Co
1133 	Seritech
1135 	Acer
1136 	Sun's Electronics Co
1138 	Win-Win Elecronic Co
1140 	Angine Limited Taiwan Branch (H. K.)
1141 	Nuseed Technology Inc
1142 	Firich Enterprises Co
1143 	Crete Systems Inc
1144 	Vista Technology Co
1146 	Taste Corporation
1147 	Integrated Technology Express
1150 	Achitec
1151 	Accos Enterprise Co
1152 	Top-Thunder Technology Co
1154 	San Li
1156 	Technica House
1158 	Hi-Com Industrial Co
1159 	Twinhead
1161 	Monterey International Corp
1163 	Softek Systems Co
1165 	Mercury Computer Corporation
1168 	RioWorks Solutions
1169 	Microstar (MSI)
1169 	NEC
1170 	Taiwan Igel Co
1171 	Shing Yunn Electronics Enterprise Corp
1172 	Giantec
1175 	Applied Component Technology Corp
1176 	Sigma Computer Corp
1177 	High Tech Computer Corp
1178 	Clevo
1180 	Padalin International Development Corp
1181 	Leo Systems Inc
1182 	Alpha-Top Corporation
1183 	Mirle Automation Corporation
1184 	Delta Electronics
1188 	Quanta Computer
1190 	Chips and Technologies
1192 	ICP
1193 	Ser Comm Corp
1195 	Gns Technoloies Inc
1196 	Universal Scientific Industrial
1197 	Golden Way Electronic Corp
1199 	Gigabyte
1201 	New Tech
1203 	Sunrex Technology Corp
1204 	Bestekcomputer Co
1206 	Olivetti
1209 	Puretek Industrial Co
1210 	Rise Computer
1211 	DFI
1214 	Rever Computer Inc
1218 	ECS (Elitegroup)
1221 	Darter
1222 	Domex (DTC)
1223 	Biostar
1225 	Yunglin Technology Corp
1229 	Dataworld International Corp
1234 	Leadman Electronic Co
1235 	Formosa Industrial Computing
1238 	Win Tech Technology Co
1241 	Mustek
1242 	Amptek Technology Co
1244 	Flytech Group International
1246 	Cosmotech Computer Corp
1247 	Abit
1248 	Muse Technology Co
1251 	Portwell Infotech
1252 	Sono Computer
1256 	Lucky Star
1258 	Four Star Computer Co
1259 	GVC
1260 	Dt Research Inc
1262 	Arima
1266 	Modula Tech Co
1270 	Portwell Inc
1271 	Tidal Technolongies Inc
1272 	Ultima Electronics Corp
1273 	Ufo Computer Co
1274 	Full Yes
1275 	Jackson Dai Industrial Co
1276 	Jetway
1277 	Trangg Bow
1281 	EFA
1283 	Advance Creative Computer Corp
1284 	Lung Hwa Electronics Co
1286 	Askey
1291 	TMC (Taiwan MyComp Corporation)
1292 	Asus
1297 	DD&TT Enterprise Inc
1299 	Trigem
1301 	Taken
1304 	Dual Enterprises Corporation
1309 	Protronic Enterprises Corp
1317 	New Comm Technology Co
1318 	Unitron
1323 	Inventec
1343 	Shuttle (Holco)
1346 	Snobol Industrial Corp
1347 	PC Chips (Hsin Tech)
1351 	Singdak Electronic Co
1353 	J-Bond
1354 	Protech Systems
1355 	Arrgo Systems Inc
1367 	Coxswain Technology Co
1371 	ADI
1373 	Silicon Integrated Systems Corp
1379 	WinTechnologies (Edom)
1391 	Aten International Co
1392 	Acc Taiwan Inc
1393 	Plato Technology Co
1396 	Tatung
1398 	Spring Circle
1400 	Key Win Electronics
1403 	Uniwill
1404 	Alptech Logic Products Inc
1421 	Well Join Industry
1422 	Labway Computer Co
1425 	Lindata Corp
1437 	PC Chips (Hsin Tech)
1440 	Great Electronics Corporation
1450 	Win Lan
1451 	Ecel Systems Corp
1452 	United Hitech Corporation
1453 	Kaimei
1461 	Hedonic Computer Co
1462 	Arche Technologies Inc
1470 	Free Tech
1470 	Flexus Computer Technology
1472 	Datacom Technology Co
1484 	Mitac
1490 	Great Tek Corp
1491 	President Technology Inc
1493 	Artdex Computer Corp
1494 	Pro Team Computer Corp
1500 	Netcon Co
1503 	Up Right Tech Co
1514 	Wuu Lin Electronics Co
1519 	EPoX
1526 	Eagle Computer Technology Co
1531 	Force System Inc
1540 	BCM
1546 	Golden Horse Computer Co
1549 	Ct Continental Corp
1564 	Random Technology Inc
1576 	Jetta
1585 	Gleem Industries Co
1588 	Boser
1593 	Advantech
1594 	Mitac
1608 	CMC
1612 	Datavan International
1617 	Honotron Corporation
1618 	Union Genius Computer Co
1621 	New Paradise Enterprise Co
1622 	R.P.T. Intergroups International
1628 	Digital Equipment International
1630 	Iston Computer Corp
1647 	Lantic Inc
1652 	Ase Technologise Inc
1655 	Kingston Technology Inc
1656 	Storage System Inc
1658 	Macrotek
1666 	Cast Technology Inc
1671 	Cordial Far East Corp
1672 	Lapro Corporation
1675 	Advanced Scientific Corp
1685 	High Ability Computer Co
1691 	Gain Technology Co
1697 	Olivetti
1700 	Dsg Technology Inc
1707 	Chaining Computer & Communiction Co
1708 	E-San Electronic Co
1719 	Taiwan Turbo Technology Co
1720 	Fantas Technology Co
1723 	Ntk Computer Inc
1737 	Ay Ruey International Co
1739 	Jetpro Infotech Co
1743 	Mitac
1759 	BEK-Tronic Technology
1762 	Ansoon Technology Co
1770 	AOpen
1771 	Toyen Computer Co
1774 	Acer Sertek Inc
1776 	Joss Technology
1780 	Acrosser
1783 	Efar Microsystems, Inc Taiwan Bran
1788 	Systex Corporation
1792 	U-Board
1794 	Cmt-Taiwan, Inc
1796 	J&J Technology
1800 	Syzygia Computer Corporation
1801 	Palit Microsystems Inc
1806 	Interplanetary Information Co
1807 	Expert Electronic Corp
1810 	Elechands International Co
1815 	Powertech
1820 	Ovis Enterprises Co
1823 	Inlog Microsystem
1826 	Tercomputer Technologies Corp
1827 	Anpro Inc
1828 	AXIOM
1840 	New Union H.K. New Union H.K.
1845 	Pc Direct Technology Co
1846 	Garnet International Corp
1847 	Brain Power Co
1850 	Htr Asia Pacific Inc
1853 	Veridata Electronics Inc
1856 	Smart D&M Technology
1867 	Lth Rong Electronic Enterprise Co
1868 	Soyo
1879 	Aeontech International Co
188 	Quanta Computer
1881 	Manufacturing Technology Resources
1888 	Seal International Corp
1889 	Rock Technology Lo
1906 	Freedom Data Technology Co
1914 	Aquarius Systems Inc
1917 	Source Of Computer Co
1918 	Lanner Electronics
1920 	Ipex Itg International
1924 	Join Incorporation
1926 	Kou Sheng Computer Co
1927 	Seahill Technology Co
1928 	Nexcom International Co
1929 	Cam Enterprise Inc
1931 	Aaeon
1932 	Kuei Hao Industrial Co
1933 	Asmt Corp
1934 	Silver Bally Inc
1935 	Prodisti Co
1936 	Codegen Technology Co
1937 	Orientech Electronics Corp,
1938 	Project Information Company,
1939 	Arbor Technology Corp
1940 	Suntop Computer Systems Corp
1941 	Funtech Entertainment Corp
1942 	Sunflower Systems Inc
1943 	Needs System Development Co
1945 	Norm Advanced Technology Corporation
1947 	Ten Yun Co
1948 	Beneon Co
1949 	National Advantages Computer Inc
1950 	Mits Technology Co,
1951 	Macromate Corp
1953 	Orlycon Enterprise Co
1954 	Chung Yu Electronics Co
1955 	Yamashita
1957 	High Large Corporation.
1958 	Young Micro Systems
1959 	Fastfame Technology Co., Ltd.
1960 	Acqutek Corporation
1961 	Deson Trade Inc
1962 	Astra Communication Corp
1963 	Dimensions Electronics Co
1964 	Micron Design Technology Limited
1965 	Cantta Enterprises Co
1968 	Khi Way Enterprise Co
1969 	Gemlight
1970 	Mat Technologies Limited Norm Advanced Technology Corp
1973 	Fugutech
1974 	Green Taiwan Computer Co
1975 	Supertone Electronic Co
1977 	AT&T Taiwan Telecommunications Co
1978 	Winco
1980 	Teryang Systems Co
1981 	Nexcom International Co
1982 	China Semiconductor Corporation
1985 	Top Union Electronics Corp
1986 	Dmp Electronics Co
1988 	Concierge Co, Ctd.
1989 	Atherton Technology Co
1990 	Expen Tech
1994 	Japan Cere'Bro Computers Inc
1996 	Ikon Technologies Corporation
1998 	Sono Computer
3642 	AMI
4500 	PcPartner
4668 	AMI
4707 	AMI
4724 	AMI
5701 	AMI
5706 	AMI
5711 	AMI
5721 	AMI
5722 	AMI
5727 	AMI
6063 	IBM
6064 	AIR
6100 	Unika
6105 	Dolch computer systems
6132 	Technology Power Enterprises
6154 	Sprite Inc.
6156 	Genoa
6247 	TTC Computer Products Irving
6259 	VEGA
6259 	Young Micro
6285 	Tyan
6326 	Crystal
6328 	Alaris
6333 	Addtech
6362 	Northgate Computer Systems Inc
6362 	Seanix
6385 	HP
6386 	Pacific Information, Inc
6389 	Supermicro
6395 	Lion Computer
6423 	APC
6666 	CTL Corp
6730 	AMI
6735 	AMI
6745 	AMI
6750 	AMI
6759 	AMI
6770 	AMI
6774 	AMI
6781 	AMI
6782 	AMI
7803 	AMI
8003 	QDI
8021 	Acer
8028 	Wellstar
8031 	Zida
8036 	DTK
8045 	VTech
8045 	PcPartner
8045 	Aristo
8054 	Pine Technology
8060 	GB486 Computer systems
8200 	Gateway
891E 	Veridata Electronics Inc 
9999 	Generic code

AMIBIOS keyboard controller (KBC) codes:
0	Almost always means command A1 (return KBC revision) has not returned a byte
5	AMI Megakey KB-5 (1995) (Copyright string returned by command A0 is 1994), most often seen on NSC and SM(S)C Super I/O chips
7	Unknown AMI clone
8	AMI '8'
9	Everex AMI
A	V-Tech chipset on-chip AMI clone
B	AMI 'B'
D	AMI 'D'
E	AMI 'E', also seen on some ALi M1489 boards when the output of the Read Command Byte Command gets mixed up for A1 output
F	AMIKEY (original) or its clone
H	AMIKEY-2 or its clone, AMIKEY-2 is seen on ITE and Winbond Super I/O chips
M	MR (Microid Research) AMI clone from 1991
P	AMI Megakey (1993)
R	AMI Megakey (1994) (Copyright string returned by command A0 is 1993)
X	Most likely AMIKEY-3 for the 388xx, seen on a NEC LaVie C laptop
U	SARC 6042, also seen on some ALi M1489 boards when the output of the Read Command Byte Command gets mixed up for A1 output
Z	TriGem AMI, two variants exist - normal (based on 'F') and green (based on some revision of Megakey)