HP-97S I/O testing

[TellyS]

Hi Hiwi,

It is indeed a remarkable calculator, probably one of my top favorite HPs. I purchased one on eBay a long time ago, but it was not working. I decided to replace all ICs on the interface in hopes that the problem was there. There is only one HP-proprietary ROM chip for which a replacement probably does not exist. Luckily that chip was fine. It worked! I have attached a picture of the board with the replaced ICs in case someone wants to do the same.

I ran several programs on it, but my favorite is something I built using a BASIC STAMP processor and a voice module. Commands could be given to the 97S via voice.
Video is located here: https://spyropoulos.net/files/TalkingCalculator.mp4
(Apologies for the low resolution video. It's several years old. I will have to redo with Arduino.)

Telly