HP41C with Rp Pico attached

[ThomasF]

(09-06-2023 02:51 PM)MeindertKuipers Wrote:  Hello all,

Just published a first working base version of my HP41 RP2040 interface.

Hi Meindert!

Thanks for sharing - looks like you have been very busy ...
(I know I have promised to clean up my code and make it available too ...)

Your implementation of PIOs looks very interesting!

I also started with Andrews code as a base, and have managed to get MLDL emulation, full display mirroring (with 41 font emulation and annunciators) and trace with disassembly in "realtime" (to terminal on PC) up and running.

At the moment I have two ROMs (just now PPC and ZenRom are loaded) and 1 page of RAM for the MLDL (saved in flash to survive reboot and power loss), and I'm looking for a filesystem or tool to be able to replace the ROM/RAM flash image easily from the PC (over USB) without the need to re-flash the Pico.

I build mine using the Tiny2040 (smaller footprint but less gpio's - and 4 components in total (Pico, display, levelshifter and one single driver)), and my next plan is to also include the FI signal (I think I still have two pins available and have to add a second driver) and hope to be able to emulate the wand buffer.
Mainly just because it is fun and educational and secondly to very easily be able to transfer programs from a PC to the calculator.

Hope to find some rainy days to be able to continue the work ...

Cheers,
Thomas