I'm pretty sure CP/M 86 was already a thing. I believe there was even Concurrent CP/M 86, which let you run up to 4 (or more?) virtual sessions concurrently. Light years ahead of MS-DOS but nobody wanted it, so DRI dumbed it down and added MS-DOS compatibility and re-released as DR-DOS (still superior to MS-DOS though).
CP/M-86 was definitely a thing, but CP/M-386 was not. By the time the 386 existed, DRI had dropped the CP/M name in favour of Concurrent DOS - though they had MS-DOS compatibility in Concurrent CP/M - and, as you say, eventually renamed it to DR-DOS.
Much as I loved DR-DOS, it did have occasional compatibility hiccups.
cp/m-86 targets 8086, which is no more useful or relevant to 386 protected mode than the original z80 version. Did you think they just picked the 68k version at random?
> cp/m-86 targets 8086, which is no more useful or relevant to 386 protected mode than the original z80 version. Did you think they just picked the 68k version at random?
The big reason for picking the 68K version is it was mainly written in C (initially in Pascal, but they later switched to C.) By contrast, the more famous 8080 versions were largely written in assembly, as was the 8086 version.
Well, CP/M-80 1.x was mostly written in PL/M, a dialect of PL/I developed by Gary Kildall, but CP/M-80 2.x+ was rewritten in assembly for speed; PL/M was still used for some of the utilities. Obviously, C compilers are much easier to come by nowadays than PL/M compilers are.
Just as some off-the-top history, MS-DOS was clearly obsolete, but it hung around for like 10 years too long because people couldn't quit it. It was a DOSSY DOS world.
"Protected Mode DOS" went through the IBM/MS gristmill and became OS/2, which was a compromised product in a lot of ways. Then Windows (still mostly a DOS program) got a little traction, and Microsoft had hired Dave Cutler to write a real OS. And David overthrew Goliath and the rest is history. On topic, nobody really wanted protected-mode DOS or CP/M etc.
Wasn't that abbreviation from "pipe"? As in - this is a pipe that you can use to connect terminal to a file, file to a printer... and yes, file to a file (that's cp/copy).
Much as I loved DR-DOS, it did have occasional compatibility hiccups.
The big reason for picking the 68K version is it was mainly written in C (initially in Pascal, but they later switched to C.) By contrast, the more famous 8080 versions were largely written in assembly, as was the 8086 version.
Well, CP/M-80 1.x was mostly written in PL/M, a dialect of PL/I developed by Gary Kildall, but CP/M-80 2.x+ was rewritten in assembly for speed; PL/M was still used for some of the utilities. Obviously, C compilers are much easier to come by nowadays than PL/M compilers are.
"Protected Mode DOS" went through the IBM/MS gristmill and became OS/2, which was a compromised product in a lot of ways. Then Windows (still mostly a DOS program) got a little traction, and Microsoft had hired Dave Cutler to write a real OS. And David overthrew Goliath and the rest is history. On topic, nobody really wanted protected-mode DOS or CP/M etc.
https://en.wikipedia.org/wiki/Peripheral_Interchange_Program
Looks good!
An order of magnitude (or two!) less code complexity and less memory hungry than most of 2026's bloated Operating Systems...
Well done!
"Full 32‑bit protected mode implementation"
That being said, banked 32-bit "mode" does exist, and it's weird: https://en.wikipedia.org/wiki/Unreal_mode