AMI Hi-Flex BIOS

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The Hi-Flex BIOS POST screen

Not to be confused with the Hi-Flex Setup Utility on AMIBIOS 6 and AMIBIOS 7.

AMI Hi-Flex BIOS, unofficially nicknamed AMI Color BIOS (due to the various color presets available in its default setup utility), is a version of AMIBIOS released by American Megatrends (AMI) in late 1990 as a successor to the AMI Plus BIOS. It introduced an updated POST screen, a new setup utility with various menus and a new identification string format that would be used in all newer AMIBIOS versions.

POST screen

Although similar, the Hi-Flex BIOS POST screen has some changes compared to AMI Plus BIOS'. The most noticeable changes are with the identification string and the memory test.

Identification string

Main page: Identification string (BIOS)

Hi-Flex BIOS introduced a new identification string format that is more detailed than the older formats. This format was also re-used for all newer versions of AMIBIOS and even the CSM module in Aptio, AMI's modern UEFI firmware that replaced AMIBIOS in the late-2000s and the early-2010s.

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

  • C: Processor/platform architecture
    • "2" indicates an i286 based or compatible system
    • "3" indicates an i386 based or compatible system
    • "4" indicates an i486 based or compatible system
    • "5" indicates an i586 based or compatible system
    • "6" indicates an i686 or AMD64 (x64) based or compatible system
    • "7" is irregular from the format and occasionally indicates an AMIBIOS 07.00.xx ROM, as seen on the AMI Olympus II motherboard
  • R: ROM size
    • "0" indicates a 64 kilobyte ROM size
    • "1" indicates a 128 kilobyte ROM size but is occasionally also reused for 1 and 2 megabyte ROM sizes
    • "2" indicates a 256 kilobyte ROM size
    • "3" indicates a 512 kilobyte ROM size but is commonly also reused for larger ROM sizes on Aptio
    • "4" indicates a 1 megabyte ROM size
    • "5" indicates a 2 megabyte ROM size
    • "6" indicates a 4 megabyte ROM size
    • "7" indicates an 8 megabyte ROM size
    • "8" indicates a 16 megabyte ROM size
    • "9" indicates a 32 megabyte ROM size
  • VVVV: ROM revision number given by the OEM (not to be confused with the AMIBIOS revision release date)
  • 00: Unknown or reserved, may be a different number from 00 in occasion
  • MMMM: OEM/BIOS licensee code
  • FFFFFFFF: BIOS feature set indicator (usually 00101111)
  • SSSSSS: AMIBIOS revision release date (or ROM compile date on AMIBIOS 07.00.xx and AMIBIOS 8)
  • DDDDDDDD: ROM identifier (usually the motherboard chipset name)
  • K: Keyboard controller (KBC) type
    • "0" usually indicates an unknown KBC
    • "5" indicates an AMI Megakey (1995) KBC or a clone (usually on NSC and SMC/SMSC Super I/O chips)
    • "7" indicates an unknown AMI KBC clone
    • "8" indicates an early AMI KBC
    • "9" indicates an AMI KBC used by Everex
    • "A" indicates a V-Tech chipset with an integrated AMI KBC clone

Memory test

On AMI Plus BIOS and older versions, the entire system memory is tested slowly by default during POST, unless the test is sped up by pressing the option key to "skip" the test (usually the Escape key). On Hi-Flex, this behavior was changed so that only base memory is tested slowly (usually the first 640 kilobytes), while extended memory (the rest) is tested fast to reduce the POST time. Because of this, the option to "skip" the memory test was also removed with Hi-Flex, but was later brought back with AMI WinBIOS in 1993.

Copyright string

On early revisions, the copyright string at the top of the POST screen began with the words "ROM BIOS", as it did on later revisions of AMI Plus BIOS. Beginning with revision 060692 (June 6, 1992), it was changed to say "AMIBIOS" instead of "ROM BIOS". Otherwise, the string is unchanged from Plus BIOS.

Setup utility

All instances of Hi-Flex BIOS include a built-in setup utility, with the default setup utility from AMI being the most common (except for code forks). This utility, unlike previous default utilities, lists options in different menus for organization (with each menu containing relevant options). This also inspired the default setup utility introduced by Award Software for EliteBIOS in 1993.

This utility also introduced color presets for the first time, with 16 presets included by default (as shown below).

Technical limitations

Lack of Logical Block Addressing (LBA) support

Similar to the AMI Plus BIOS, hard drives of up to 32 GB in capacity can be configured in the setup utility. However, due to the lack of LBA (Logical Block Addressing) in most revisions, only up to 504 MB can actually be utilized. Although, some late revisions of Hi-Flex BIOS support LBA. On these revisions, LBA can often be enabled in the Advanced CMOS Setup menu. Various workarounds also exist for this limitation, such as using Ontrack Disk Manager.

New ROM identification string format

As mentioned, Hi-Flex BIOS has introduced the string format that was in use for all newer versions of AMIBIOS and all versions Aptio until 2020 (when the string was finally removed), with only some slight changes over time.

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 later cores of AMIBIOS 6 and later releases. The keyboard controller ID is also not used on AMIBIOS 07.00.xx, AMIBIOS 8 and Aptio.

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").

For a list of codes for each field, click here.

Intel fork

Main page: List of BIOS and UEFI firmware used by Intel motherboards

Intel has forked AMI Hi-Flex BIOS core version 111192 and used it on most of their motherboards manufactured from 1993 to 1997 (when they switched to PhoenixBIOS 4.0 Release 6.0 instead). Early versions of this fork are not much different from the original AMI version, while later versions had a lot more differences. This fork was also used by most OEMs that licensed Intel motherboards for their computers, although sometimes with their own branding and occasionally even their own setup utility (like with Dell and IBM).