HP Spectrum analyzer EEROM - Page 1
Forum section: electronics / testgear

author: Big Dog
author_rank: Contributor
timestamp: February 19, 2016, 04:18:47 am
content: Hi everyone,I am posting this here in hopes that someone out there can help me with a MAJOR mistake!I erased the EEPROM to my HP70900B Local Oscillator, this in turns kills using the Spectrum analyzer,and other instruments in the system.So, if there is anyone out there with a HP 70900B that is willing to read their EEPROM,or if you had a spare ROM board, I would love your help.My firmware version is 900314 and if your unit has a serial number between:3022A00558 to 3033A00707. Reading the EEPROMs is all that’s needed.Serial numbers before this can be used, but your unit must be a B unit.Serial numbers after mine can only be used, if you are able to send the whole ROM/RAM board.Serial Numbers 3414A01968 and above will only work, if the controller board is 7090-60143.I know this is a lot to ask of someone, but know that you will be helping a poor student and disabled vet.Thank you all for your attention.The Big Dog

author: mojoe
author_rank: Frequent Contributor
timestamp: February 19, 2016, 05:44:07 pm
content: http://www.ko4bb.com/getsimple/index.php?id=manualsDo a search on 70900B to find what you need.

author: Big Dog
author_rank: Contributor
timestamp: February 19, 2016, 06:05:57 pm
content: Quote from: mojoe on February 19, 2016, 05:44:07 pmI know the site well and it dose not have what I need, It has two firmware listed, the first is for a 70900A, and the second is for the very last firmware made.the first one will not work as it is for an A version, as stated by HP, it will not work, and I tried it and it does not work.the last one made will not work with my system as it uses 1M EEPROM and mine uses 512Meg.In order to use that last firmware listed there, I would need a new firmware card and a new CPU card as well.If the problem was that easy I would not have made a very detailed post as to what was needed.

author: mojoe
author_rank: Frequent Contributor
timestamp: February 19, 2016, 11:14:03 pm
content: Well, since I can't read minds, I didn't know that you were had already checked that site. Excuse me for trying to help you. I won't make that mistake again.

author: KE5FX
author_rank: Super Contributor
timestamp: February 20, 2016, 12:38:42 am
content: One option may be to hack the necessary address decoding logic to map the 1M chips to the existing bus. The CPU board will send one or more of its high-order address lines through a multiplexer that drives the chip select pins on the 512KB EPROMs. If you can find the A19 line, you may be able to move it to the A19 pins on the 1M parts. A20 and above would then drive the CS pins, just as A19+ did originally.Check with the hp_agilent_equipment group on Yahoo before warming up the soldering iron, though. Sometimes people will back up their firmware and not upload it to the KO4BB or Blue Feather FTP sites...

author: TheSteve
author_rank: Unknown
timestamp: February 20, 2016, 12:59:20 am
content: Quote from: KE5FX on February 20, 2016, 12:38:42 amThis option may have the added bonus of having a newer firmware rev, seems like a fun potential mod if the board is compatible.

author: Big Dog
author_rank: Contributor
timestamp: February 20, 2016, 02:41:22 am
content: Quote from: KE5FX on February 20, 2016, 12:38:42 amI tried to join that group some time back, and never got the invite.I do know the board I have can not fit a 1meg eprom or flash chip, and that there is more ram on the newer boards as well.I was hopeing to just get my unit back up at this point.

author: Big Dog
author_rank: Contributor
timestamp: February 20, 2016, 03:19:15 am
content: Quote from: mojoe on February 19, 2016, 11:14:03 pmThis is a repost, as some thing happened to the first reply.Sorry I was so short with you, but when someone pops in without reading or understanding a thread, it does get to me.As people will think the problem is solved, and pay the post no mind.What the bigger problem is that this is the same kind of mistake that started all this in the first place.so my response is more about being pissed at myself for not reading the full info from KOB44 site in the first place.So in short you have my full apology for being rude in my reply to you.

author: Big Dog
author_rank: Contributor
timestamp: February 22, 2016, 07:42:12 pm
content: Hi everyone,A ham operator read a post elsewhere and sent me the files and posted them to KO4BB site as well.Just wanted to say thanks for everyones input.