AMIBIOS 2.2x: Difference between revisions

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[[File:AMIBIOS_2.2x_POST.png|thumb|POST screen of AMIBIOS 2.2x subcore 013189]]
[[File:AMIBIOS_2.2x_POST.png|thumb|POST screen of AMIBIOS 2.2x revision 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 [http://mrbios.com/techsupport/award/postcodes.htm the POST code list of the unofficial MR BIOS website].
AMIBIOS 2.2x (name assumed) is a version of [[AMIBIOS]] released in 1986. It was first developed by Access Methods and then by [[American Megatrends]] (after they acquired the AMIBIOS source code). This version is also mentioned in [http://mrbios.com/techsupport/award/postcodes.htm the POST code list of the unofficial MR BIOS website], which is where the naming of this version is assumed from.


== POST screen ==
== POST screen ==
The POST screen is almost completely different from the one seen on [[AMIBIOS Rev-X2-03|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 POST screen is almost completely different from the (likely earlier) one seen on [[AMIBIOS Rev-X2-03|Rev-X2-03 (AMIBIOS 2.03)]] and also on the later [[AMI Plus BIOS]]. Assuming Rev-X2-03 was released before it, visible changes on the AMIBIOS 2.2x POST screen would be the removal of extra spacing in the "(CPU)-BIOS" text at the top and the inclusion of another AMI copyright right next to it. The new copyright also includes the copyright year(s).


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.
A quirk with the new copyright is the inclusion of multiple years, with the first often indicating 1985. Although this may indicate AMIBIOS 2.2x was released in 1985 instead, that is likely for the year of the foundation of Access Methods instead.
 
The memory test counter has also been changed. The new counter now tests the total memory, rather than testing base and expanded memory separately.


== String ==
== 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 <code>MMMM-SSSSSS</code> 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.
AMIBIOS 2.2x is also the earliest known version of AMIBIOS to include a proper BIOS string in the POST screen. This early string is in the <code>MMMM-SSSSSS</code> format (<code>MMMM</code> for manufacturer code and <code>SSSSSS</code> for the BIOS revision release 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 release from January 31, 1989 (<code>013189</code> in string), which despite being released quite late, lacks it. The string is also referred to as a "Reference number" with some revisions of this version.
 
The following string format is used:


=== String format: ===
'''MMMM:''' Manufacturer/OEM identification code, '''SSSSSS:''' BIOS subcore release date
'''MMMM:''' Manufacturer/OEM identification code, '''SSSSSS:''' BIOS subcore release date


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'''Example string''': 1406-061286
'''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").
This string is for a 06/12/86 (June 12, 1986; date is in American format) dated revision of AMIBIOS 2.2x for Flying Triumph Co. Ltd. ("1406").


For a list of manufacturer identification codes, refer [[:Document:AMIBIOS string codes|here.]]
For a list of manufacturer identification codes, refer to the BIOS string codes list on SoftHistory Wiki [[:Document:AMIBIOS string codes|here.]]

Latest revision as of 17:29, 29 April 2024

POST screen of AMIBIOS 2.2x revision 013189

AMIBIOS 2.2x (name assumed) is a version of AMIBIOS released in 1986. It was first developed by Access Methods and then by American Megatrends (after they acquired the AMIBIOS source code). This version is also mentioned in the POST code list of the unofficial MR BIOS website, which is where the naming of this version is assumed from.

POST screen

The POST screen is almost completely different from the (likely earlier) one seen on Rev-X2-03 (AMIBIOS 2.03) and also on the later AMI Plus BIOS. Assuming Rev-X2-03 was released before it, visible changes on the AMIBIOS 2.2x POST screen would be the removal of extra spacing in the "(CPU)-BIOS" text at the top and the inclusion of another AMI copyright right next to it. The new copyright also includes the copyright year(s).

A quirk with the new copyright is the inclusion of multiple years, with the first often indicating 1985. Although this may indicate AMIBIOS 2.2x was released in 1985 instead, that is likely for the year of the foundation of Access Methods instead.

The memory test counter has also been changed. The new counter now tests the total memory, rather than testing base and expanded memory separately.

String

AMIBIOS 2.2x is also the earliest known version of AMIBIOS to include a proper BIOS string in the POST screen. This early string is in the MMMM-SSSSSS format (MMMM for manufacturer code and SSSSSS for the BIOS revision release 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 release from January 31, 1989 (013189 in string), which despite being released quite late, lacks it. The string is also referred to as a "Reference number" with some revisions of this version.

String format:

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 revision of AMIBIOS 2.2x for Flying Triumph Co. Ltd. ("1406").

For a list of manufacturer identification codes, refer to the BIOS string codes list on SoftHistory Wiki here.