HP97 The journey begins

[teenix]

Hi all,

Boy what a few days. I've had enough bugs to keep the worlds bird population happy. I spent all of today trying to find a card read bug. As you might expect there is some complex code that has to execute and finding bugs in code that interacts with real hardware can be tricky. It turned out to be a comma [,] at the end of one code line that wasn't supposed to be there and the compiler did not report an error. Just about needed a magnifier to see it. [sigh]

Anyways, some good news.

The new board appears to be functional except for a [barely perceptible] flicker on the display which I will try to sort out.
I ran both sides of the HP-67 diagnostics card through the reader and it ran and gave the correct result.
I have successfully written cards and re-read them and the programs run as expected.
The original HP software also reads/writes "cards" from the external memory as it thinks it is talking to the CRC chip.
The PC software does the hardware re-flashing, transfers card data back and forth and sets a few operating options.

I still have to check the auto card read where the card is "parked" in the slot and the program encounters a Pause command, but as that is controlled by HP software, it should work - yeah right :-)

Time for a snoozzzzzzze.

cheers

Tony