AMIBIOS Rev-X2-03: Difference between revisions

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[[File:AMIBIOS_Rev-X2-03_POST.png|thumb|POST screen of AMIBIOS subcore Rev-X2-03]]
[[File:AMIBIOS_Rev-X2-03_POST.png|thumb|POST screen of AMIBIOS subcore Rev-X2-03]]
AMIBIOS Rev-X2-03 is a subcore for an unknown core version of [[AMIBIOS]], assumed to be made by Access Methods (which then would sold AMIBIOS to [[American Megatrends]]). This specific subcore is assumed to be released in 1985 or early-1986.
AMIBIOS Rev-X2-03 is a version of [[AMIBIOS]], assumed to be made by Access Methods (which then would sell AMIBIOS to [[American Megatrends]]). This specific subcore is assumed to have been released in 1985 or early-1986.


Rev-X2-03 seen on an IBM XT clone motherboard [https://www.youtube.com/watch?v=4AD3sgvuBNs demonstrated by the YouTube channel Dfgrt924]. This is believed to be the earliest known subcore of AMIBIOS with proof to confirm it's existence.
It can be seen on an unknown IBM XT clone motherboard [https://www.youtube.com/watch?v=4AD3sgvuBNs demonstrated by the YouTube channel Dfgrt924]. This is believed to be the earliest known subcore of AMIBIOS with proof to confirm it's existence.


== POST screen ==
== POST screen ==
The POST screen is different from all other known versions of AMIBIOS. The 8088-BIOS text at the top and the memory test counters all look different. This version also has two memory counters (one for base system memory and other for expanded memory that could be additionally installed), instead of only one as seen in newer versions.
The POST screen is different from all other known versions of AMIBIOS. It also has two memory counters (one for base system memory and other for expanded memory that could be additionally installed), instead of only one as seen on other versions.


This version also seems to lack a proper BIOS string, while AMIBIOS 2.2x already had a string, indicating the string was introduced with 2.2x or a slightly earlier version. It says "Rev-X2-03" where the string would go with future versions.
This version also seems to lack a proper BIOS string, while AMIBIOS 2.2x already had a string, indicating the string was introduced with 2.2x or a slightly earlier version. It says "Rev-X2-03" where the string would go with future versions.


The BIOS also lacks a setup launch prompt, which is usual for early IBM PC compatible BIOSes. Built-in setup utilities started becoming common in around 1987.
The BIOS also lacks a setup launch prompt, which may indicate the BIOS was compiled before 1987 as that's around when a setup utility was introduced.


== Boot error messages ==
== Boot error messages ==
There are two boot errors seen in the demonstration, the first error message that reads <code>Drive not ready Insert diskette in A: Press any key .....</code> appears when a floppy drive is either not installed or can't boot to a disk yet. While the second <code>Boot failure Insert diskette in A: Press any key .....</code> error appears when there is not a valid boot disk in the drive. These messages are similar to the ones seen on newer AMIBIOS versions, although slightly different.
There are two boot errors seen in the demonstration, and they are slightly different compared to the error messages seen on other versions of AMIBIOS.
 
'''First error:'''
 
<code>Drive not ready</code>
 
 
<code>Insert diskette in A:</code>
 
<code>Press any key .....</code>  
 
 
'''Second error:'''
 
<code>Boot failure</code>
 
 
<code>Insert diskette in A:</code>
 
<code>Press any key .....</code>

Revision as of 17:31, 15 December 2023

POST screen of AMIBIOS subcore Rev-X2-03

AMIBIOS Rev-X2-03 is a version of AMIBIOS, assumed to be made by Access Methods (which then would sell AMIBIOS to American Megatrends). This specific subcore is assumed to have been released in 1985 or early-1986.

It can be seen on an unknown IBM XT clone motherboard demonstrated by the YouTube channel Dfgrt924. This is believed to be the earliest known subcore of AMIBIOS with proof to confirm it's existence.

POST screen

The POST screen is different from all other known versions of AMIBIOS. It also has two memory counters (one for base system memory and other for expanded memory that could be additionally installed), instead of only one as seen on other versions.

This version also seems to lack a proper BIOS string, while AMIBIOS 2.2x already had a string, indicating the string was introduced with 2.2x or a slightly earlier version. It says "Rev-X2-03" where the string would go with future versions.

The BIOS also lacks a setup launch prompt, which may indicate the BIOS was compiled before 1987 as that's around when a setup utility was introduced.

Boot error messages

There are two boot errors seen in the demonstration, and they are slightly different compared to the error messages seen on other versions of AMIBIOS.

First error:

Drive not ready


Insert diskette in A:

Press any key .....


Second error:

Boot failure


Insert diskette in A:

Press any key .....