!Re: Nuke Redmond! - test-drb@ccmp.vtda.org

7 Apr 2000

...
 class) machines; hind sight and all that.  And I'm
not even saying it was
wrong for Tim Patterson to model the OS calls after CP/M.  After all, that's
...
 what he knew. 

Ahem, pattern after?  it was wholesale copy of CPM1.3 lofted to 8086
after which the ALLOC code was replaced with FAT.  (saved buffer space in
ram)

...
   I would say that the roots of MS-DOS 1.x are entirely
in CP/M, while with
2.x the influence of other operating systems (notably Unix) start to show 

This is very true.  Mostly because of the copying that was done.  DOS 2.0
had to
have similar functionality and yet be different plus CPM and DOS 1.0 lacked
some needed features seen in VMS, UNIX, and others.

...
 up.  Then again, CP/M wasn't created wholecloth
either, it had roots from
RT-11 (I think that's the OS), which Gary Kildall had experience with. 

True but the user appearance is only similar, the internal differences
are significant.  (Actually it was TOPS10 and OS/8) but they differ even
more.

...
 > I've heard that, too.  Does that mean that
anyone who writes a program to do
...
   what he's
seen another program do is making a copy? 
  Ask the lawyers or philosophers.

> You're not even sure he
> actually saw and read the source code.  How many programmers do you know
> who'd simply copy someone else's work in a case like this?  Everybody
wants
...
 > to leave his own mark. 

By then most everyone had disassembled CPM and it was a trivial task as it
was
only 3.5k of 8080 code!  Legit copies were even available to some people.
Also there were clones of CPM (P2dos for example) and Turbodos.

Allison