AMIBIOS Rev-X2-03: Difference between revisions

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[[File:AMIBIOS_Rev-X2-03_POST.png|thumb|POST screen of AMIBIOS 2.03]]
[[File:AMIBIOS_Rev-X2-03_POST.png|thumb|The POST screen as seen in a YouTube video]]
AMIBIOS 2.0x is the second main release of [[AMIBIOS]], made by Access Methods (which then sold AMIBIOS to [[American Megatrends]]). AMIBIOS 2.0x also has been labelled as AMIBIOS Rev-X2-0x, with x indicating subversion. AMIBIOS 2.0x is assumed to be released in 1985 or early-1986.
AMIBIOS "Rev-X2-03" (possibly officially called AMIBIOS 2.03) is a version of [[AMIBIOS]], assumed to be made by Access Methods Inc., which then would sell the AMIBIOS code and trademark to [[American Megatrends]]. This version is assumed to have been released in 1985 or early 1986.


So far, the only known instance of AMIBIOS 2.0x is AMIBIOS 2.03 (labelled as 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 version of AMIBIOS with proof to confirm it's existence.
The only known instance of it is seen on an IBM XT clone motherboard (possibly [https://theretroweb.com/motherboards/s/unknown-xt-12#bios this model], as the layout is similar), as demonstrated in a YouTube video made by the user Dfgrt924<ref>https://www.youtube.com/watch?v=4AD3sgvuBNs</ref>. This is believed to be the earliest known version of AMIBIOS with proof to confirm its 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 visually different from all other known versions of AMIBIOS. It also has two memory test counters (one for base memory and the other for expanded memory) instead of a single merged counter as seen in 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 either 2.1x or 2.2x. It says "Rev-X2-03" where the string would go with future versions.
This version also lacks a ROM identification string, with only the copyright and revision being shown where it would usually go. As [[AMIBIOS 2.2x]] already had one, the string may have been introduced with that.


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.
It also lacks a setup entrance prompt, which likely indicates it does not contain a built-in setup utility. This may also confirm it was released before 1987 (as the earliest known instances of AMIBIOS with it were released around that time). However, as built-in setups are uncommon on 8088-based ROMs overall (usually even on later ones), this does not certainly indicate such a thing.


== Boot error messages ==
== 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 error messages seen in the video, and they are slightly different compared to the error messages seen on other versions of AMIBIOS.
 
'''Floppy drive not ready message:'''
 
<code>Drive not ready</code>
 
 
 
<code>Insert diskette in A:</code>
 
<code>Press any key .....</code>  
 
 
 
'''Floppy drive boot failure message:'''
 
<code>Boot failure</code>
 
 
 
<code>Insert diskette in A:</code>
 
<code>Press any key .....</code>

Latest revision as of 15:57, 13 June 2024

The POST screen as seen in a YouTube video

AMIBIOS "Rev-X2-03" (possibly officially called AMIBIOS 2.03) is a version of AMIBIOS, assumed to be made by Access Methods Inc., which then would sell the AMIBIOS code and trademark to American Megatrends. This version is assumed to have been released in 1985 or early 1986.

The only known instance of it is seen on an IBM XT clone motherboard (possibly this model, as the layout is similar), as demonstrated in a YouTube video made by the user Dfgrt924[1]. This is believed to be the earliest known version of AMIBIOS with proof to confirm its existence.

POST screen

The POST screen is visually different from all other known versions of AMIBIOS. It also has two memory test counters (one for base memory and the other for expanded memory) instead of a single merged counter as seen in other versions.

This version also lacks a ROM identification string, with only the copyright and revision being shown where it would usually go. As AMIBIOS 2.2x already had one, the string may have been introduced with that.

It also lacks a setup entrance prompt, which likely indicates it does not contain a built-in setup utility. This may also confirm it was released before 1987 (as the earliest known instances of AMIBIOS with it were released around that time). However, as built-in setups are uncommon on 8088-based ROMs overall (usually even on later ones), this does not certainly indicate such a thing.

Error messages

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

Floppy drive not ready message:

Drive not ready


Insert diskette in A:

Press any key .....


Floppy drive boot failure message:

Boot failure


Insert diskette in A:

Press any key .....