Compaq Portable motherboard, late revision?

[MissArgent]

So, I'm still hacking away at the Baby Blue and i've switched over to my Compaq Portable, the machine I intend it to go in. While poking around (and cleaning up some embarrassing early socket/replace work on the 8237 from years ago), I remembered something unusual: The motherboard doesn't really match anything I've seen on the internet. It can take 256k in 4164 DRAMs or 41464 DRAMs, using a shunt jumper to control which DRAMs the machine uses. Is this a very late run machine, or something weird? I can't think of many PC clones or even XT clones that can use 41464. Hell, the Portable Plus motherboard seemingly doesn't even really line up with this one.

 

[jafir]

Interesting. Is there an “assembly” number on it somewhere? Also what BIOS revision is in it?

 

[MissArgent]

Interesting. Is there an “assembly” number on it somewhere? Also what BIOS revision is in it?

Motherboard assembly 000385-001, Rev. A. BIOS revision is J (106265-002). Machine was bought off a construction contractor on the outskirts of Chicago a few years back. (I recently had to replace that selection shunt pack with a spare DIP switch since I accidentally pulled the entire socket while trying to get the shunt pack out)

 

[dhau]

Rev. J is from 1987, which makes it one of the very last portables built. I have two, and both are from 1985, which I assume was the peak year for Portable.

There is a dump of Rev. J from Mr. @jafir, but I have a few Rev. H with different checksums. If you don't mind, please dump your bios and either compare it to Jafir's dump or share it here and I'll do the comparison.