First post, by Deksor
- Rank
- l33t
Hello,
since I've started the project UH19, I have been thinking about something kinda crazy which I can't do myself, but that would be interesting for many people in my opinion which involves understanding AMI bioses better (and perhaps other bioses as well, but the 64KB AMI bioses are probably the simplest to mess with and the most common).
What if we tried to document old AMI bioses better ? After comparing many bioses of the same version (050591), I came to the conclusion that even when their target differ (different chipset, different kind of processor), there are many similarities among them.
Actually most of the differences seemed to be caused by some large sections being put in a different place (but containing the same data by the look of it).
So this made me wonder : if we can understand what (some ?) of these sections do, this means that if find something useful to modify into one, we could make a patching program to patch every AMI bios of the same version ?
See where I am going ?
My idea is that if we can understand how old AMI bioses deal with the HDD, then maybe we could replace that code with some XT-IDE code and get rid entirely of the 503MB limit once and for all without the need of any additional hardware !
Another example for 386 motherboards ; we could probably implement support for the L1 cache of the Cyrix 486DLC that later boards had to older boards.
Furthermore, maybe this could let us add some more features such as CD-ROM boot, floppy disk drive swap, etc ?
Maybe we could even try to build BIOSes for motherboards using a different chipset that was only supported by really old (1980's) AMI bioses to implement better features ? This could be handy for some obscure OEM computers that were made with a very limited BIOS (such as one of my 286 which has a nice "NEAT" chipset, but a really bad phoenix bios with a really small selection of HDDs supported and no support for hardware functions such as memory shadowing).
With the growing size of UH19's BIOS database and people dumping their BIOSes in other places, the amount of BIOSes people can easily download and test has never been so large and so diverse. Moreover, we now have emulators such as PCem/86box that are advanced enough for easy testing (without the risk of ruining precious hardware).
What do you think ? Is it too crazy ? Another idea that will be scrapped in a week ? Any of you interested ?
Trying to identify old hardware ? Visit The retro web - Project's thread The Retro Web project - a stason.org/TH99 alternative