HP41C with Rp Pico attached

[blackjetrock]

(06-01-2023 05:53 AM)ThomasF Wrote:  I.e. the Wand is quite "simple", and emulating that up to 16 bytes are available to be sent shouldn't be that hard to implement, dividing a program into 16 bytes chunks and feed them to the emulation of the module.
But, I've not seen any commented listing of the Wand ROM, so it might take a while to decode the processing, emulating the hardware connected to the module ...

Having a ROM image and information about the hardware will be almost essential. One thing that makes this project possible is that there is a lot of information about the 41C and it's peripherals.

Quote:If successful we could then use a battery powered Pico or similar device with WiFi or Bluetooth, and it should be possible to wireless transfer programs to the 41 - a dream come through!

unfortunately the RP2040 (Pico IC) isn't a very low power device. It is low-ish power consumption so battery power is definitely an option but it isn't anywhere as low power as the HP41C itself, for instance.

Quote:With the Card Reader it would also be possible to send program from the 41, but that's another story ...

Is the card reader well documented?

Quote:Another possibility would be to emulate X-Memory, and enable the Pico to send or receive programs to be stored in the XM, ie use the XM as a dual port memory - allowing a PC to read and write to that memory in realtime. The layout of the XM filesystem is well known, so that might be an easier approach (but not as fun as emulating hardware IMHO).

As the Pico has the ROM that is being emulated in it's flash memory then you can already send and receive programs in ROM format to and from a PC by re-programming the Pico. The Pico code is actually storing the data in RAM and so it can be changed on the fly with the code on Github now. You'd need to add USB CLI commands to read/write RAM, but that's easy. There's also a Pico W with wireless built in, and I have used an external module to do Bluetooth with the Pico as well.

i think the XM module would be a good one to look at. As you say it is well known and so the code emulation should be straightforward. I think the circuitry for the Pico can be shrunk to a module size using the RP2040 IC, so it might be possible to put this in a module housing. A USB module should be simple, from the hardware side, it's just a matter of deciding what to emulate. Although, it should be able to emulate anything I suppose...

Quote:For me it sound like a very interesting thing to dive into, and I have already ordered some Pico's to play with ...

When I order the PCBs I get 5 minimum, so I could send you a PCB if you want? PM me.

Quote:Just wishing that time was something you could order online as well ...

Oh yes.


Cheers,
Thomas
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