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Full Version: Is this from an HP-97s?
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I'm asking in the name of someone else who is no longer on this forum:

What is this connector on hp-97?



I don't know what is going on with all the wires, but the PCB looks like the one in my HP97.

Not a 97S. Looks like someone hacked up a 97 to connect an external keyboard.

I have a 97 converted to a 97S by adding a connector with multiple wires inside. I don't know the exact wiring, but I would think this is exactly what happened here. To the best of my knowledge, both calculators have the same hard- and software, and only the Centronics plug is missing on the 97.

The wiring shown is not for the correct set of signals for a 97S conversion.

Also, the difference between a 97 and a 97S is a LOT more than just wires and a so-called "Centronics" (actually "Delta Ribbon" or "CHAMP") interface connector. There's a whole BOX full of electronics that interfaces between the base calculator and the interface connector.

Edited: 8 Feb 2013, 4:22 p.m.


I have a 97S and I just picked up another 97 that someone wired up a serial connector to. Was there a way to duplicate the 97S like this?

Sure, if you build a clone of the external box. It contained two boards full of SSI/MSI chips.

Or, using modern technology, you could probably do it using a PIC microcontroller, but the trick would be to write the firmware.

Was there a way to duplicate the 97S like this?

Yes, here's how.

katie, what would we do without her!

There's no question that it's impressive work, but it doesn't seem to me that it's a "duplicate" of the 97S.


Hi Tom! It's been a crazy long time, hope all is well with you.

Agreed. There's much in the 97s pod that's not being duplicated at all. Monitoring and decoding the instructions to determine when the flags are set and cleared is the big missing piece. The pod also reads a full word of BCD data in parallel and outputs it (serially) to the calculator. While this would be an easy addition to the program, it would require some additional hardware, or a processor with a lot more input pins.

I was just answering AJ's question:

Was there a way to duplicate the 97S like this?

As 'yes' there's a way and pointing to a description of roughly how to do it not claiming that I had done it all.

Busy with lots of things that are not calculator related, but my collection (most of it) made it up to my new office in the barn and I do get to see them on a regular basis. I still have a Wang that I need to bring back to life, but that is a long term project.