Oh look, some tumbleweed…..

Actually, there has been progress on the homebrew Z80 system!

No actual hardware yet, but I now have a working simulator, with the beginnings of a Z80SIO serial I/O simulator. This correctly intercepts all the I/O port access that the chip understands, and displays the state of all the registers on screen, with an interpretation: rather than just dumping the raw register contents, it describes what each bit or bit group is intended to do, i.e. 7-bit data, 2 stop bits, receive interrupt enabled.

I’ve got a prototype perl script communicating back-to-back with minicom via a pseudo-terminal; now to reimplement this in C, and wire it into the SIO simulator.

Getting the pty code controlled by the register access is going to be tricky.

Then it’s time to write a quick ‘local echo’ test program in Z80, and off we go…..

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