AMIBIOS Rev-X2-03: Difference between revisions

From SoftHistory
No edit summary
No edit summary
 
(3 intermediate revisions by the same user not shown)
Line 1: Line 1:
[[File:AMIBIOS_Rev-X2-03_POST.png|thumb|POST screen of AMIBIOS subcore Rev-X2-03]]
[[File:AMIBIOS_Rev-X2-03_POST.png|thumb|The POST screen as seen in a YouTube video]]
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.
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.


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.
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. 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.
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 2.2x or a slightly earlier version. 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 may indicate the BIOS was compiled before 1987 as that's around when a setup utility was introduced.
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, and they are slightly different compared to the error messages seen on other versions of AMIBIOS.
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.


'''First error:'''
'''Floppy drive not ready message:'''


<code>Drive not ready</code>
<code>Drive not ready</code>




Line 24: Line 25:




'''Second error:'''
 
'''Floppy drive boot failure message:'''


<code>Boot failure</code>
<code>Boot failure</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 .....