HP Classic Series Display Driver

[Harald]

A little update on the progress. The first prototype boards are here:



Mechanically they fit quite well. I think the holes for the connectors to the keyboard PCB could be 1/10 of a mm smaller, but they work OK.

The large Microchip PIC on the left (yes, I could have used a smaller surface mount package, but decided against it) runs Tonys (teenix) emulation. IC3 is the eeprom to emulate the card reader for the HP65 and HP67. IC4 is an FTDI chip to connect the PIC to the PC via USB. It should be possible to cut a hole in the battery compartment and plug a cable in from inside the battery compartment.
Finally the square chip on the right is a renesas microcontroller running my software that reads the display data sent by Tonys PIC and outputs that to the original display drivers on the keyboard PCB.

Now the software needs more work. So far the HP35, 45 and 80 work.
Tony has already been very helpfull and has done a lot of work adapting his code to scan the original 8 rows by 5 coulums keyboard rather than the 6x6 setup he is using in his hardware emulator.
Some of the caluclator models don't run yet and I am not sure why. I struggle a bit to work my way through Tonys (impressive!!) PIC assembler code. I am sure there will be progress when Tonys time permits to work on this again.

Cheers,
Harald