• PDOS for C64

    From Paul Edwards@mutazilah@gmail.com to comp.sys.cbm on Friday, April 02, 2021 14:35:51
    From Newsgroup: comp.sys.cbm

    I have an MSDOS-like OS which currently works on the 8086,
    80386 and S/3X0 (mainframes). You can see it here:

    http://pdos.sourceforge.net/

    I think it's too big to be ported to the Commodore 64,
    and I've always wondered what options I have. I note
    that the C128 has a Z80 coprocessor, and I was thinking
    why stop there - why not have an 80386 coprocessor
    so that PDOS/386 can run.

    I was thinking that PDOS would sit outside of the 64k
    address space, except for some stubs. A C64 emulator
    for Windows could also load my 80386 PDOS kernel,
    and then when PDOS needed to write to the screen, it
    would either directly write to the C64 display memory,
    or request the C64 emulator to do that.

    The C64 user would be presented (on their normal
    40*25 screen I think it is), an MSDOS prompt and
    be able to do a "dir" of an emulated disk, which
    would include a PDOS/386 micro-emacs executable
    which used ANSI codes which are translated by
    PDOS/386 into C64 character display buffer updates.

    C64 executables would also reside on the FAT-16 disk,
    possibly in ELF format.

    The C64 executables would not be normal C64
    programs, they would receive a callback function
    on startup, and use that to request standard C90
    services like fopen()/fread() so you have the full
    C library available and can open any file on the
    FAT-16 disk.

    But when not requesting file services, or malloc(),
    the C64 6502 code would have normal access to
    the full C64 hardware (as provided by the emulator,
    although theoretically a real machine could be
    built too).

    The callback functions would be 6502 stubs that
    switch processor to 80386 using some mechanism
    enabled by the C64 emulator.

    Any thoughts?

    BFN. Paul.
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  • From Chris Baird@cjb+usenet@brushtail.apana.org.au to comp.sys.cbm on Monday, April 19, 2021 09:50:08
    From Newsgroup: comp.sys.cbm

    Any thoughts?

    It makes me think of FORTH's Remote Target Compilers--
    albeit with the interactive session being on the C64's
    side.

    --
    Chris,,
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