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 for all newer AMIBIOS versions and even early instances of Aptio, AMI's UEFI firmware.

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

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.

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).