开云体育

Hello group! I did build my Z80 Membership Card, and it has been some fun. ?I intended to use it as a basic Z80 cpu board in an unrelated project, but figured I should play with it in its native form before changing the firmware. ?I'm impressed with the work that clearly went into it.

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I did not get to use CP/M back in the day since it was expensive, so it was fun to explore now. ?It's amazing what we considered a system back then; lol.

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While I can code in assembly, I prefer to do things in C where possible, and I'm using SDCC. ?I had to set up a CRT0 that was appropriate for CP/M and the Z80MC in particular. ?SDCC provides a pretty rich implementation of libc, but stdio is lacking since file i/o is system dependent. ?So I did what any programmer would do and implemented the parts of stdio for doing the FILE* stuff, e.g. fopen(), fclose(), fread/write/printf, etc. ?(and malloc seemed broken so I adjusted for that.)

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Anyway, I don't know if anyone has interest in coding in C for CP/M, but if so I'm putting some files in the file space. ?This includes stdio-cpm-example-20241207a.zip, which contains a demo project exercising the library, along with the libs and headers for writing your own stuff. ?If you just want to run the test program first without building, there is also a disk image STDIOEX.BIN that can be mounted via CPMDISKS.TXT (I replace DISK-D.BIN with that), and then you can run STDIOEX.COM directly from it. ?It will printf some stuff, get keyboard input, and open, read, and write files showing stuff along the way. ?The source 'main.c' should be useful in showing how to construct a program. (I mean, it's standard C, but the headers and parsing the command line is different.) ?There are also the build scripts so you can see how to set up for assembling, compiling, and linking. ?You're on your own for installing SDCC! ?I think you can manage! ?It's easy! ?You might like cpmtools for manipulating disk images.

I need to clean up the library code then I'll put it on github for anyone curious to see the internals. ?I'm still implementing stuff (e.g. scanf(); yikes.)

Cheers!
-dave