most modern design for an HP41 rom module?

[ThomasF]

There is also the Raspberry Pico solution.

Not only has it an "unlimited" flash space for all modules, but also resources and capabilities to emulate HW modules. Today we emulate the Wand, IR-Printer module, HP-IL (over USB) and the ET-11967 Service Module. Also RAM and XMEM is emulated (with flash backup etc).

And with USB connection to a PC, configuring the device (eg switching modules) is easy.

It even allows adding new peripheral instructions - e.g. I made a MCode program that can send a Focal program to the PC over USB or IR (see another posting for all details).

It also allows for real time tracing of the bus (all signals) - like a logic analyzer.

And the best thing is that it is a open device allowing anyone to program it to add new features (a development board is currently available).

It is not a really low power device but I use mine with a LiPo battery without any problems, and a miniature PCB (long module format) is being developed (search for Pico or Tulip) on this forum for more information.

Cheers,
Thomas