Compaq Portable III modded BIOS / XTIDE

Discussion about old PC hardware.

Compaq Portable III modded BIOS / XTIDE

Postby LeFlash » 2018-9-16 @ 19:33

Hi there,

while restoring my Compaq P3 i had some interesting thoughts.

First of all, this machine got an IDE->CF-adapter in the drive bay. Second, a Gotek.
But i didn't want to use Ontrack, so i checked what the 2 empty ROM-sockets are doing.
Turned out they are mapped at E000h. The Bios unfortunately only checks from C000 - DF80h for extension roms.
So i patched the BIOS to scan up to EF80h and removed its CRC-routine to make things easiert. Split XTIDE-Bios in Lo/Hi,
burned and voilá! Works like a charm. :-)

Now i'll get a ATBus expansion box and fiddle out the pinout of the internal connectors. Next plan is to change the built-in CGA-gpu to something
newer, maybe Trident. Hopefully all needed Pins are present.

Anyway, if anyone is interested in the patched bios, let me know!

Kind regards!
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Re: Compaq Portable III modded BIOS / XTIDE

Postby Jo22 » 2018-9-16 @ 23:37

Hi, that's a neat (or nifty) thing you did. Congrats! :D
While I've got no Compaq Portable III myself, I think this would indeed be useful to any Compaq owner.

Best regards,
"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel

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