Re: CP/M bootable CD?

Thanks for the encouragement, folks. Sounds like this might be a project
worth doing!

Allison wrote:
Interesting idea. You'd have to use one of the CP/M clones (P2dos,
Zrdos and friends) to get around the 8mb limit of DRI CP/M. But
having an emulator for a nice CP/M system (maybe even a full boat
emulation) that "just runs" from a CD would likely be popular.

When it comes to emulators, my favorites are MyZ80 and Dave Dunfield's
Horizon as they suit my particular likes and needs.

Yes; CP/M-80 is what I had in mind. I'm more familiar with it, and it's
the harder problem (CP/M-86 is easier to get working, so people
shouldn't need as much help).

My thought is that booting the CD would give you a CP/M emulation of
some classic CP/M computer. The PC's keyboard, screen, serial, and
parallel ports would work the same as the machine being emulated.

As for disk drives: I assume that the CP/M A: drive would actually be a
RAM disk, that comes up already loaded with all the usual CP/M files
(boot tracks, ccp, bdos, stat, pip, asm, load, etc.). It would also have
a typical selection of application programs; editors, languages, etc.

If all you ever used was the A: drive, the CP/M emulator would leave no
"footprint" in the PC. It wouldn't alter anything on the PC, but you
would lose whatever work you did.

The B: and C: drives might be the PC's floppy and hard drive. These
would give you a way to save data so it would be there the next time you
booted the CP/M-CD. The file formats would probably be PC formats, as no
classic CP/M computer would have worked with 1.44meg floppies or our
huge modern hard drives anyway. However, if only your data files are on
the B: drive, a single 1.44meg disk can hold a *lot* of CP/M work! With
your CD and this 1.44meg floppy, you can carry your CP/M world to any
computer.

As for how CP/M would deal with the huge CD: My (rather naive) thought
is that the CD could appear to CP/M as a huge box of floppy disks, each
under 8 megs. Each of these simulated floppies is in a directory
(CPMUG-v.050, GAMES.001, etc.) We provide a CP/M program to mount one
of these directories as the D: drive. For example, "mount cpmug-v.050"
makes this subdirectory on the CD become the CP/M emulator's D: drive.
This would allow one to select any disk, type its readme files, pip
files back and forth, etc. Crude, but it has the right "feel" for an old
CP/M system.

The first challenge may be to pick a good CP/M emulator. I'm not really
happy with the ones I have; they all make many compromises to be
DOS-like rather than CP/M-like. They require renaming .COM files as
..CPM, or don't have a real BDOS or CCP, or don't emulate any CP/M style
terminal, or other things that cause many CP/M programs not to work.
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
.

Relevant Pages

  • Re: The way things were "back in the day"
    ... It was Tandy's disk operating system. ... IMHO it was better than CP/M. ... Tandy it was media swapping or more drives. ... disk of any kind you were among the elite due to it's cost. ...
    (comp.os.cpm)
  • Re: Double space or similiar for CP/M
    ... for CP/M that would would automatically compress / decompress files on ... are floppy based only and have limited disk storage. ... which were intended to help people with small floppy disk drives. ...
    (comp.os.cpm)
  • Re: Starting from scratch
    ... >but I always lusted after a real cp/m machine to play with. ... and then has the biggest hard drive a Microbee ever saw. ... relied on a machine that had the same disk drive. ... drives. ...
    (comp.os.cpm)
  • Re: Need help with bootable CP/M disk
    ... > working S-100 cp/m system to make a bootable disk, ... Maybe a different format? ... inch drives with 3.5 inch drives. ...
    (comp.os.cpm)
  • Re: more history (was:Re: GIDE interface kits)
    ... CP/M 2.2 was invented to use an 8" floppy disk drive, ... floppy drives being developed by Alan Shugart for IBM (probably from ... and IO system for Intels new CPU to support development tools. ...
    (comp.os.cpm)