AMIBIOS 2.2x

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Revision as of 17:12, 22 January 2024 by Rueni97 (talk | contribs)
POST screen of AMIBIOS 2.2x subcore 013189

AMIBIOS 2.2x is a version of AMIBIOS released in 1986. It was developed first by Access Methods and then by American Megatrends after the AMIBIOS purchase. This version is also mentioned in the POST code list of the unofficial MR BIOS website.

POST screen

The POST screen is almost completely different from the one seen on Rev-X2-03 (AMIBIOS 2.03). The extra spaces in the "(CPU)-BIOS" text at the top has been removed, and another AMI copyright has been put next to it. The new copyright also includes the copyright year. While the former copyright year says 1985, it's likely for when Access Methods was found rather than when AMIBIOS 2.2x was first released.

The second memory counter for expanded memory has also been merged with the base memory string. The new merged memory counter now counts the total memory, rather than counting base and expanded memory separately.

String

AMIBIOS 2.2x is also the earliest known version of AMIBIOS to include a proper BIOS string in POST screen. The string for early versions is in the MMMM-SSSSSS format (MMMM for manufacturer code and SSSSSS for subcore date). According to The BIOS Companion, later cores should include a newer string format that is also seen on AMI Plus BIOS. However a known 013189 release, which despite being late, lacks it. The string is also referred to as a "Reference number" with some subcores of this version.

The following string format is used:

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").

For a list of manufacturer identification codes, refer here.