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Electronics => Repair => Topic started by: NE666 on December 05, 2024, 07:59:46 pm

Title: Looking for HP 3325A ROM Images
Post by: NE666 on December 05, 2024, 07:59:46 pm
Hello.

As per the title, I'm hoping that someone on the forum is able to either provide me with, or point me in the direction of, ROM images for the 4 ROM version of the 3325A Synthesizer/Function Generator. I've been able to locate images for the successor 3325B online ('K04BB' website) but not for the A version.

I recently came into possession of one that I'm using as much for exercising my diagnostic and repair chops on, as anything else. So far, my investigations suggest that (as a minimum) the U1 ROM has failed. I'd like to be able to either emulate or substitute a replacement in order to test that theory.

Thanks.
Title: Re: Looking for HP 3325A ROM Images
Post by: fzabkar on December 05, 2024, 11:09:40 pm
Can you upload your ROM images?
Title: Re: Looking for HP 3325A ROM Images
Post by: picburner on December 06, 2024, 03:42:08 am
Actually on the Ko4bb site there are the files of the 3325A but for only two eproms. Are there different hardware versions of the same instrument?

Edit: However, the two 8KB eprom files found on the Ko4bb site can be converted into 4 x 4KB files for your instrument, as someone at HP/Agilent in groups.io did.
Title: Re: Looking for HP 3325A ROM Images
Post by: TERRA Operative on December 06, 2024, 03:57:32 am
I have two 3325A, I'll check this weekend if they have what you need.
Title: Re: Looking for HP 3325A ROM Images
Post by: NE666 on December 06, 2024, 10:24:04 am
Quote from: picburner on December 06, 2024, 03:42:08 am
Actually on the Ko4bb site there are the files of the 3325A but for only two eproms.

Would you mind providing a link to where you saw those? I'd thought I'd made a good search of that site, yet only found the 'B' version of FW. Even the section on 3325A has only images marked as being for the B.

Quote from: picburner on December 06, 2024, 03:42:08 am
Are there different hardware versions of the same instrument?

Yes, I believe that to be the case, based on threads I've returned during Google searches. The suggestion being that HP flipped between 2 and 4 ROM (sometimes using EPROMs) variants during the production lifetime of the 'A' version, where they needed to because of supply issues. The subsequent 'B' version had many HW changes and improvements, especially to the logic and control board, including a different processor, so the 'B' ROMs certainly can't be used in the 'A'.

Quote from: picburner on December 06, 2024, 03:42:08 am
Edit: However, the two 8KB eprom files found on the Ko4bb site can be converted into 4 x 4KB files for your instrument, as someone at HP/Agilent in groups.io did.

Again, might I trouble you for a link? I've been unable to locate that discussion.

Thanks for your help.
Title: Re: Looking for HP 3325A ROM Images
Post by: squadchannel on December 06, 2024, 10:59:31 am
This?
https://www.ko4bb.com/getsimple/index.php?id=download&file=HP_Agilent_Keysight/HP_3325A_Synthesizer/HP_3325A_Synthesized_Function_Generator_EPROM.zip (https://www.ko4bb.com/getsimple/index.php?id=download&file=HP_Agilent_Keysight/HP_3325A_Synthesizer/HP_3325A_Synthesized_Function_Generator_EPROM.zip)
Title: Re: Looking for HP 3325A ROM Images
Post by: NE666 on December 06, 2024, 12:53:28 pm
Quote from: squadchannel on December 06, 2024, 10:59:31 am
This?
https://www.ko4bb.com/getsimple/index.php?id=download&file=HP_Agilent_Keysight/HP_3325A_Synthesizer/HP_3325A_Synthesized_Function_Generator_EPROM.zip (https://www.ko4bb.com/getsimple/index.php?id=download&file=HP_Agilent_Keysight/HP_3325A_Synthesizer/HP_3325A_Synthesized_Function_Generator_EPROM.zip)

Yes!

Sorry, with apologies to all, I clearly couldn't make out the wood for the trees last night. It was right there in plain sight but I guess I was just drawn to the folder entry marked firmware (for the 3324B) and missed the obvious link above.

Many thanks.
Title: Re: Looking for HP 3325A ROM Images
Post by: picburner on December 06, 2024, 04:17:11 pm
Quote from: NE666 on December 06, 2024, 10:24:04 am
Again, might I trouble you for a link? I've been unable to locate that discussion.

The discussion I was talking about should be this (https://groups.io/g/HP-Agilent-Keysight-equipment/topic/3325a_roms/24809732?p=Created,,,20,1,40,0)
Title: Re: Looking for HP 3325A ROM Images
Post by: Dan N on December 07, 2024, 03:00:32 pm
Be aware that the original ROMs (Synertek SY2332) had custom programmed chip select pin behavior.  U1/U3 connect to the same select line with one ROM configured active low the other active high.  Same for U2/U4.

You'll have to determine if the one you replace needs an inverter on the select signal (details in the thread link posted above by picburner)
Title: Re: Looking for HP 3325A ROM Images
Post by: 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
Title: Re: Looking for HP 3325A ROM Images
Post by: fzabkar on December 08, 2024, 08:30:44 pm
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: [Select]
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.........

Code: [Select]
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

There is also this "key check":

Code: [Select]
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......
Title: Re: Looking for HP 3325A ROM Images
Post by: fzabkar on December 08, 2024, 08:31:55 pm
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

I can split them ...
Title: Re: Looking for HP 3325A ROM Images
Post by: TERRA Operative on December 08, 2024, 11:36:34 pm
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...
Title: Re: Looking for HP 3325A ROM Images
Post by: fzabkar on December 09, 2024, 12:20:38 am
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...

Some discussion here ...

https://groups.io/g/HP-Agilent-Keysight-equipment/message/73495 (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 (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
Title: Re: Looking for HP 3325A ROM Images
Post by: NE666 on December 09, 2024, 09:35:37 pm
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.