I added buttons to the Nonpareil printer support for the “print” and “paper advance” functions, and radio buttons for the MAN/TRACE/NORM switch. I’ve posted an updated screenshot.
There’s an interesting bug. When the calculator is not in PROGRAM mode, the print and paper advance buttons behave mostly as expected. In program mode, the print button works OK (puts a PRX or PRA in the program). But if you press the paper advance button, the simulated 41 starts reporting “OUT OF PAPER”. And once it starts doing that, there’s no way to get it to stop. I’ve verified with the debugger that my printer code NEVER returns status to the 41 with the OOP status bit set.
I haven’t much of a clue what’s going wrong. One hypothesis is that perhaps this results from my simulated printer being instantaneous; it never returns a BUSY status. I could add some code to make it return BUSY for a while.