Electronics > Repair

Looking for HP 3325A ROM Images

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fzabkar:
I merged the two 64KB dumps (alternating low and high bytes) and found 2 references to a checksum, but I wasn't able to locate it or determine the algorithm.


--- Code: ---Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F

0001BA70  0B 64 6F 5F 72 65 63 61 6C 6C 3A 20 1A 64 6F 5F  .do_recall: .do_
0001BA80  72 65 63 61 6C 6C 3A 20 63 68 65 63 6B 73 75 6D  recall: checksum
0001BA90  20 66 61 69 6C 65 64 00 00 00 00 00 00 00 00 00   failed.........
--- End code ---


--- Code: ---Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F

0001E8C0  4E 5E 4E 75 53 41 56 45 20 48 4F 4F 4B 53 20 20  N^NuSAVE HOOKS 
0001E8D0  20 20 20 20 20 20 20 20 0F 63 68 65 63 6B 73 75          .checksu
0001E8E0  6D 20 66 61 69 6C 65 64 13 69 6E 69 74 69 61 6C  m failed.initial
0001E8F0  69 7A 69 6E 67 20 71 75 65 75 65 73 13 65 6E 61  izing queues.ena
0001E900  62 6C 69 6E 67 20 69 6E 74 65 72 72 75 70 74 73  bling interrupts
--- End code ---

There is also this "key check":


--- Code: ---Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F

00018A90  FF E0 52 08 4E B9 00 00 CE 7E 4E 5E 4E 75 09 6B  ÿàR.N¹..Î~N^Nu.k
00018AA0  65 79 5F 63 68 65 63 6B 3F 97 8D 4F DF 3B 64 5B  ey_check?—.Oß;d[
00018AB0  3F B9 99 99 99 99 99 9A 3F F0 00 00 00 00 00 00  ?¹™™™™™š?ð......
--- End code ---

fzabkar:

--- Quote from: TERRA Operative on December 08, 2024, 01:22:09 pm ---I checked my two instruments, but unfortunately they are both models without the 4 ROM chips
--- End quote ---

I can split them ...

TERRA Operative:
Here are the EPROM dumps from one of my 3325A with two chips.

The other 3325A I have has 3 chips, one chip is the "HP 3325A A6U2 Rev A 070 03325-19402 PCB-RevC" included below, plus it has two NEC chips with these two HP part numbers: 1818-0702, 1818-0704. I'm not sure what they actually are though...

fzabkar:

--- Quote from: TERRA Operative on December 08, 2024, 11:36:34 pm ---... plus it has two NEC chips with these two HP part numbers: 1818-0702, 1818-0704. I'm not sure what they actually are though...
--- End quote ---

Some discussion here ...

https://groups.io/g/HP-Agilent-Keysight-equipment/message/73495

FWIW, there is a uPD2332 on page 106:

https://mirrorservice.org/sites/www.bitsavers.org/components/nec/_dataBooks/1979_NEC_Microcomputer_Catalog.pdf


--- Quote ---Two Programmable Chip Select Inputs for Easy Memory ExpanSion
--- End quote ---

NE666:
Just a quick note at this point to express my gratitude to everyone who has given their time to offer assistance. Thank you.

I plan to spend some time with the patient over the Christmas holidays and I'll update on how that goes, for the future reference of others.

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