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CP/M source more open now

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whartung

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retronic.us

CP/M is really open-source now

Bryan Sparks, President of DRDOS, clarified the license of CP/M: Let this paragraph represent a right to use, distribute, modify, enhance, and otherwise make available in a nonexclusive manner CP/M and its derivatives. This right comes from the company, DRDOS, Inc.'s purchase of Digital...
retronic.us retronic.us

Rather than a formal license, it's a clarification from Bryan Sparks about the status of CP/M source code.

A real license would be better, who knows if that's forthcoming.

But the intent from the post is at least clearer as to the status of CP/M source code and its distributability.
 
I think it's pretty obvious
Anything with "CP/M" in it's name
Concurrent DOS > DOS Plus > DR DOS is right out
 
Al Kossow said:
I think it's pretty obvious
Anything with "CP/M" in it's name
Concurrent DOS > DOS Plus > DR DOS is right out
Click to expand...
fundamentally because it is built on a completely different code base
it also seems like this push for clairity isn't coming from x86 folks
 
Would be awfully nice if something could be done for DR-DOS though. The DR-DOS Inc website has been gone since 2018 so I assume Bryan Sparks is no longer selling licenses for it - perhaps it could be open-sourced too?

Additionally, Caldera OpenDOS / DR-DOS was never really free - they only ever released the source code for a few bits and the license was that of a trial version but with out a fixed end date rather than open source or freeware: "Caldera grants you a non-exclusive license to use the Software in source or binary form free of charge if your use of the Software is for the purpose of evaluating whether to purchase an ongoing license to the Software. The evaluation period for use by or on behalf of a commercial entity is limited to 90 days; evaluation use by others is not subject to this 90 day limit but is still limited to a reasonable period".
 
This is great news ! :)

Are there any good copies of CP/M 3 or similar in z80 mnemonics that can be readily compiled as a starting point for modification? Where's the best point to start when rolling your own?

Thanks
David
 
cj7hawk said:
So now is probably a good time to assert once more that MSDOS was copied from CP/M
Click to expand...
Except that it wasn't. There are certainly similarities, but internally they're quite different.

MS-DOS, like most other systems, stood on the shoulders of someone else and then charted its own path.
 
I’d like that too. I never really figured out how to do the whole zcpr thing.

(tried to quote cj7hawk, but failed…
 
Last edited:
cj7hawk said:
So now is probably a good time to assert once more that MSDOS was copied from CP/M ;)
Click to expand...
CP/M file systems are meh..
At least they didn't copy that.
The lack of a single set of floppy disk formats was just stupid in CP/M.
Chuck probably has 150 of them by now in 22disk
At least IBM was a forcing function for that in DOS
There was just a long discussion about the origins of FAT and its connection to standalone disk basic
 
cj7hawk said:
This is great news ! :)

Are there any good copies of CP/M 3 or similar in z80 mnemonics that can be readily compiled as a starting point for modification? Where's the best point to start when rolling your own?

Thanks
David
Click to expand...

I would recommend http://www.cpm.z80.de/download/cpm3src_unix.zip as a starting point -- it's an almost-complete copy of the CP/M 3 source configured to cross-build under UNIX (it omits INITDIR, because that's the only part written in PL/I and I couldn't find a suitable compiler at the time). It's in 8080 rather than Z80 mnemonics, because it uses Intel ASM80 to build, but a translation utility like XIZ should handle that.
 
While I'm here...

Following the recent clarification of the Digital Research CP/M licence I've bestirred myself to update my CP/M port for the PCW16 to include genuine Digital Research CP/M rather than the workalike components I'd used up to now. This means it no longer needs to have a separate startup disc that's had missing bits copied onto it from an old-style PCW.

I've also simplified the build process so it doesn't need to copy files to and from a real floppy disc.

This is, in some ways, the distribution I should have made for SD Microsystems back in 1999 when I first created PCW16 CP/M. Still, better late than never, I hope.

The only changes from 1.01 are the minimal ones necessary to support using genuine Digital Research CP/M.

You can find the 1.02 release and source code at <https://www.seasip.info/Cpm/software/>.
 
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