Adventures in Retrocomputing: hacking a 7.5 digit HP 3456A

[borghese]

Hi Simon
Is there a possibility to also have the Gerber files of the CS with LTZ1000?

[Silicium81]

I testing the firmware for 7.5 digit on my 3456A, it's work fine, thank's . To choose the firmware, I used the lsb of the GPIB address to select A16 from the daughter board. Thus, for even addresses, the original firmware is accessed, otherwise it is the 7.5-digit firmware.

I still have a few boards ... (21) If you want one, it's free for the board and 3 € for shipping cost international.

https://youtu.be/_LAhAGpToPY

More informations: https://vae-tech.forumactif.org/t259-remise-en-fonctionnement-d-un-multimetre-65-digits-hp3456a#2295

The file for programming an 27C010 (128kb memory) and memory adress plan is added in attachements

[bsdphk]

the '58A is also measuring internally to 9.5 digits and these could be seen.

Oh, my. That sounds like a project begging to happen.

You do not need to do anything special, just configure your HP3458A with OFORMAT DREAL and you will get everything it's got.

As for disassembling the HP3458 firmware:  I've done it, but I'm not sharing because it is a live product.   Stay away from the HP-IB parser and you'll be fine.

[coromonadalix]

Pimp the processor section with an raspi and a touch screen  loll

Good work guys,  impressive

For the 3458,  once the 9th digit is set,  does it stay set upon power off and power on again ?  does it flick like crazy ??