AMIBIOS 2.2x

From SoftHistory
Revision as of 11:11, 2 December 2022 by Rueni97 (talk | contribs)
POST screen of AMIBIOS 2.2x subcore 013189

AMIBIOS 2.2x is a version of AMIBIOS released in 1986 and 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 MR BIOS website.

POST screen

The POST screen is almost completely different from the one seen on Rev-X2-03 (AMIBIOS 2.03). The spaces between spaces in the "(CPU)-BIOS" wording at the top has been removed, and an 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 (2.2x was most likely released in 1986).

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.

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 core dates should include a newer string also seen on AMI Plus BIOS, however subcore 013189 despite being late lacks it. The string is also referred to as a "Reference number" with some subcores of this version.

Known subcore versions

1406-061286 (June 12, 1986)
0607-070486 (July 4, 1986)
3000-100386 (October 3, 1986)
1255-013189 (January 31, 1989)