HP 9845 Microprocessors

Micah Mabelitini accutron at woh.rr.com
Fri Jan 18 12:37:16 CST 2008

I'm trying to nail down a few bits of information regarding the various 
hybrid microprocessors contained in the earlier versions of the HP 9845. 
I recently purchased a large lot of 9845 boards, looks like most of one 
machine plus the PPU from a second machine. All told, I have four hybrid 
microprocessors. Two are the 107-pin AEC-variant 5061-3001 processor, 
one on a revision-A PPU card and one on a revision-B PPU card. The other 
two are both mounted on a single card, which is presumably a 
pre-bitslice LPU. Of the two processors on this board, one is a 
5061-3010, the other a 5061-3011. From what I understand, the -3010 is 
the original hybrid used in the 9825, and I read something somewhere 
that lead me to believe the -3011 is a microcode variant of the standard 
-3010. Are both of these processors part of the LPU? Most sources refer 
to the 9845 having two processors, the PPU and the LPU, and I haven't 
found any that say the LPU itself actually consists of two processors. 
Is the -3011 just a microcode variant of the -3010? Also, are there any 
microcode variations between the -3001 on a revision-A PPU card and one 
on a revison-B PPU card?


Micah Mabelitini

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