A quick port of ZX81's port of Greg Stanton's ProSystem Emulator. As usual most credits go to the original emulator author Greg Stanton... But for any problems with this version please contact me (see help file in archive).
Download the zip file below and copy the whole extracted directory to your SD card. For devs the source is available (of course), but its a real mess so suggest starting with Greg's or ZX81's version for other ports...