Posted by The principle used for the previous z80/CPM board support was using the WAIT signal, in response to an IORQ request from the Z80. This could not be applied to the ZX81.
I have kept the basis of previous software for memory access, the VGA output and the (non-perfect) PS2, but completely modified the Z80 interface. BUT thanks to that wonderful PSoC5 (I don’t get anything from Cypress for saying that), the hardware remains the same !!!
ZX81 needs a switchable NMI generator, some logic around NMI/HALT/WAIT, a way to force NOP on the Z80 when executing D-FILE with A15 high (while in M1), and acquisition of the D-FILE char (via FIFOin, and a DMA).
The keyboard was emulated by multiple control registers muxed together, and selected by A8-A15.
Result is :
I doubt it can be of any help, but the sources for PSoC creator are here.
Also needed would be the Eagle project :
All files here (v4 bug corrected – not manufactured).
And files to put on the uSD card, folder structure here :
Files in those folders were taken from :
Grant Searle, RC2014, S100, Z80-MBC2 and open81 in sz81.
Hello Michel,
great project!! I had the same idea (to combine a Z80 with PSoC5) but til today no time to realize it.
Therefore, i’m very interested at your project. But it is impossible to download the files. I can open the Nextcloud-site, but there are no files to load.
Can you give me a working link or can you send me the files (PSoC Creator and eagle)?
Is it possible to connect a keyboard? (maybe with PS/2)
Regards,
Peter
The links should work now.
Problem was probably caused by an update that set the hide download option.
Good luck with my files.
JJ
And yes, I made an attempt to interface with a PS/2 kbd, but
that’s not the most reliable part in the project.
I had no time to continue working on this for the past 6 months or so.
Do you have a BOM for the parts which fits best?
The output voltage of REG1117 is 3.3V?