HP1631D Logic Analyzer..Software???

Glen Slick glen.slick at gmail.com
Mon Dec 5 20:36:34 CST 2016

> Search for 1630 on http://www.ko4bb.com/ and there is a  "HP 1630A D
> 1631A D Logic Analyzer EPROM 14-Oct-1985-HP 1630A-D 1631A-D ROMs.zip"
> file with these EPROM images, which is supposed to be the latest
> version listed in the service manual for the 1630A, 1630D, 1631A,
> 1631D (but not compatible with the 1630G):
> 01630-80054
> 01630-80055
> 01630-80056
> 01630-80057
> 01630-80058
> 01630-80059
> 01630-80060
> 01630-80061
> That version should have HP-IB mass storage device support instead of
> HP-IL. Those are 16KB 27128 EPROM images. As far as I can tell from
> the service manuals some of the early versions of the 1630 CPU boards
> had 8KB 2764 EPROMs. I'm not sure if you could simply replace 2764
> EPROMs on an early CPU with 27128 EPROMs. I don't know how the 1 of 8
> chip enable decoding would work with both 8KB and 16KB parts.

To answer my own question about 2764 vs. 27128 EPROM support on the
CPU board, the schematics in the service manuals on Bitsavers are much
more readable than in the scan of the service manual I downloaded from
the HP / Agilent / Keysight website.


Schematic sheet 8B-3 shows that address lines HPA0 - HPA12 go to
address lines A0 - A12 of each EPROM in parallel, which allows for 8KB
for each EPROM, then address lines HPA13 - HPA15 go to the
demultiplexer to enable 1 of 8 EPROMs, then HPA16 goes to A13 of each
EPROM in parallel.

Inside 2764 EPROMs the HPA16 connection to A13 in the EPROM is a N/C.
With 27128 EPROMs that would allow a second bank of 64KB address space
to be mapped across the top half of the eight 16KB EPROMs.

So from the schematic it appears that if a 1630 CPU board has 2764
EPROMs it should be possible to swap those out for the final 27128
EPROM version and the address decoding should just work.  I'll find
out if that is actually true when I receive a 1630D later this week.

More information about the cctech mailing list