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Bruce Larrabee · 08-09-2015, 02:59 PM

Hello - I have a bunch of chips marked 1MA7-0166. I believe they are upgrade ROMS for the HP85. Or something close to that. They are brand new in good condition. I am offering them free to anyone that needs one (wants one?).

cruff · 08-12-2015, 12:38 AM

(08-09-2015 02:59 PM)Bruce Larrabee Wrote: Hello - I have a bunch of chips marked 1MA7-0166. I believe they are upgrade ROMS for the HP85. Or something close to that.

Do you know any more about them? Does 0166 represent a revision of the 0066 ROM? If my aging eyes read them correctly, my 85B has the following ROMs installed on the system board, with one empty socket for another.

soldered: 1MA7-0060, 1MA7-0063, 1MA7-0066, 1MA7-0068
socketed: 1MA7-0087, 1MA7-0088, 1MA7-0096

The part numbers do not seem to correspond to the ROM select codes from what I can see. Also, the 85B service manual does not list the ROM part numbers on the logic board parts list, but the 85A manual does.

Dave Frederickson · 08-12-2015, 04:02 AM

HP-85B ROM's:

1MA7-0060, U4, ROM 0
1MA7-0068, U5, ROM 1
1MA7-0066, U6, ROM 2
1MA7-0063, U7, ROM 3
1MA7-0096, U20, I/O ROM
1MA7-0087, U19, Mass Storage ROM
1MA7-0088, U18, Electronic Disc ROM

From the HP-85A/B Personal Computer Learning Guide at series80.org.

Dave

Bruce Larrabee · 08-12-2015, 04:05 PM

I don't know for certain what the chips are. It seems like they are ROMs for the HP85. But my memory has become vague on this point. I might have some info on them somewhere but I currently have no time to look for it. I'd more likely spend the time posting the same offer regarding some other chips I have. We'll see.

cruff · 08-12-2015, 11:22 PM

(08-12-2015 04:02 AM)Dave Frederickson Wrote: From the HP-85A/B Personal Computer Learning Guide

I forgot I had a copy of that! Thanks.

cruff · 08-12-2015, 11:23 PM

(08-12-2015 04:05 PM)Bruce Larrabee Wrote: I don't know for certain what the chips are. It seems like they are ROMs for the HP85.

Or possibly the 86 or 87 also?

Dave Frederickson · 08-12-2015, 11:47 PM

(08-12-2015 11:23 PM)cruff Wrote: Or possibly the 86 or 87 also?

Yes, but which one? 86A, 86B, 87, or 87XM, and lets not forget the 83.