
CP/NC – a CP/M-compatible operating system - nils-m-holm
http://t3x.org/cpnc
======
kv85s
MS-DOS user experience was extremely similar CP/M. In fact, one could safely
say MS-DOS/PC-DOS only existed in the first place as a "quick and dirty"
approximation of CP/M. (because IBM and Digital Research could not agree to
licensing terms to bring CP/M to the IBM PC)

[https://en.wikipedia.org/wiki/Digital_Research#CP/M-86_and_D...](https://en.wikipedia.org/wiki/Digital_Research#CP/M-86_and_DOS)

~~~
laumars
The story is weirder than not just agreeing to licensing terms. Gary Kildall
(of Digital Research) and IBM have wildly conflicting versions of how their
meeting went. To the point that I don't think the exact circumstances will
ever be clear.

~~~
mehrdada
I've only ever heard of the IBM/MS side of the story. Where can we find Gary
Kildall's version?

~~~
bake
It's out of print now, but "Hard Drive" by James Wallace and Jim Erickson
tells it: [https://www.amazon.com/Hard-Drive-Making-Microsoft-
Empire/dp...](https://www.amazon.com/Hard-Drive-Making-Microsoft-
Empire/dp/0471568864)

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ggm
CP/M felt like it had its roots in the same tree Tops-10 sprung from.

PIP, Peripheral Interchange Program existed in Digital Equipment, PDP series.
It was how you glued IO into the card deck and the line printer or tape
printer.

MS-DOS might well have been the category-killer 'avoid paying the IPR tax' OS,
but they also said "our customers have never seen a Digital equipment PDP
minicomputer, or mainframe. Lets do some things differently"

------
tombert
I've never had a chance to use CP/M; can someone here tell me how it compares
to something like Commodore Basic or MS-DOS?

~~~
nils-m-holm
If you have used a _very_ early version of MSDOS, its is not very different.
File names are 8+3 characters long with a dot in between, upper and lower case
is not distinguished. There are only 5 "built-in" commands: DIR, ERA (erase
files), REN (rename, but the syntax is REN NEW=OLD), SAVE, and TYPE.

There are no directories, but "user areas" numbered from 0 to 15, so different
users can have different files on the same disk. User areas are selected with
the USER command. However, most people used user areas as poor-man's
directories.

There is no COPY command. Copying files (and _much_ more) is done with a
program named PIP (peripheral interchange program). For instance,

    
    
        PIP B:=A:*.COM[E]
    

would copy all files of the type COM from drive A: to drive B: and echo the
file names.

What was great about CP/M was that it allowed programs to run on different
computers, as long as they were 8080- or Z80-based. It was a thin, but very
effective abstraction layer between the hardware and a program.

MSDOS, which was originally based on CP/M, was a step back, really, because
everybody tried to program the hardware directly instead of going through the
proper interfaces.

~~~
flyinghamster
Not only that, but CP/M itself has a rather DEC-ish flavor to it. PIP was
found on RT-11 and RSTS/E (maybe RSX-11 as well?), and the drive identifier
with a colon is also a nod to DEC.

~~~
that_jojo
VMS feels like DOS if DOS were actually secretly UNIX

Also, don't forget about OS/8 for the PDP-8 series. Very DOS-y, and released
by DEC all the way back in '71.

~~~
icedchai
VMS feels like DOS if that DOS was from another dimension. About the only
thing they have in common is "DIR" and ".EXE" extensions.

~~~
WorldMaker
Which is also why it's so fascinating Windows NT sort of merged both parallel
dimensions with its influences directly from both DOS and VMS.

------
tangue
After all these years I've just realized that my old Amstrad CPC was running
on CP/M

~~~
sedatk
Amstrad CPCs ran CP/M, but it didn't run on CP/M per se. CPCs had another OS
in the ROM called AMSDOS.

~~~
opless
And the Amstrad 1512 PCs used DOSPlus, DRIs MSDOS & CP/M crossover.

