Commodore 386SX Bridgeboard Hacks

[Jeff]

Here is my recently completed Bridgeboard with a coin cell hack, socketed oscillator, and a Cyrix 486 50mhz upgrade. It benchmarks about the same as the Vortex 486SLC-II 50mhz board!

A2386SX Bridgeboard

Does anyone remember Jordan Krim that wrote the A2386_16MB.lha file on Aminet? I was going to have a Zip to SIMM board made and do the upgrade but there is a discrepancy in the bios changes between the document and my Bridgeboard Bios as follows;

 From Jordan's document
ADDRESS     OLD DATA    NEW DATA
=======     ========    ========
73a7_____b4________ff


My A2386SX Original Binary Version 1.0
ADDRESS     OLD DATA
=======     ========
73a7_____e0

I wonder if it's a typo in the document or if there is more than 1 version of 386 Bios for 386 Bridgeboards? I tried burning it to an Eprom but the bridgeboard will no longer boot with the modified bios. Granted I haven't done the 16MB hardware mods yet. He sent me a working binary of the modified 16MB bios about 10 years ago but I seem to have lost it and I can't get a hold of him now. Has anyone done this mod successfully?

[Jeff]

The point is the modified 16MB Bios won't boot in that board. Now maybe it won't boot without the hardware mods I don't know. I didn't really want to have a Zip to SIMM board made and fit the simms without a confirmed working Bios first and my file doesn't match the Aminet doc exactly.

Oh well, maybe Jordan will turn up and remember. Until then I'm happy playing with it as is. BTW I sold my first one also. It took me years to find another one that works. Thanks to the VintageAmigan for this one.

Jeff

[Jeff]

Never too late!  Hey, how are you Jordan? I really could use a working binary of the modified bios eprom. I have (2) working 486 modified A2386's that could use the ram expansion.

Could you please send me a PM or something?

Thanks,
-Jeff