HP41C with Rp Pico attached

[blackjetrock]

(07-25-2023 03:07 PM)ThomasF Wrote:  Some progress ...

By adding a single line driver, I'm now able to drive the ISA line, and adding modules are now working.

Next step would be to add a filesystem to the Pico, so .MOD-files could be stored in flash, and then simply selected.

I also tried to modify the System Rom, and that works fine too ...
Just as a crude test I replaced a single character in one of the error messages:
https://photos.app.goo.gl/RvrCzUUGsKxQWMLG8

Code:


                if( address == 016066 ) {
                    drive_data = 001; // Replace character with an 'A'
                    drive_data_flag = 1;
                } else

Cheers,
Thomas

You could remove the system ROM and replace it all, using the RP2040 flash to store the new ROM. Then you can rewrite the system ROM entirely if you want to...

Andrew