4 ms·

>No one knows what really happened. Probably more accurate to say that no single person knows the whole story. And those that know parts of the story can't ne

>No one knows what really happened. Probably more accurate to say that no single person knows the whole story. And those that know parts of the story can't necessarily be trusted to tell the truth, either from forgotten facts, or deliberately self serving commentary. If you look at all of the stories from everyone, the facts that they all seem to agree on is that IBM went to Microsoft first, then went to Digital Research, and Microsoft came out a big winner. You could eventually buy an IBM PC with CPM, but at a much higher price. The reasoning behind those events are what's up for debate/speculation.

WalterBright 9y ago
When I bought my first PC, there was IBM PC-DOS and IBM CPM/86 at the store. DOS was $40, CPM/86 was $180 (if I recall correctly). I (and everyone else) bought DOS for that reason. Data I/O, the company I worked at, bought a few copies of CPM/86 and we tried it out. There were a few people who liked it, but most preferred DOS. Nobody could explain to me any reason to prefer CPM/86 - technical, practical, or price. CPM/86 had a shot. IBM sold both. CPM/86 lost fair and square.
- int_19h 9y ago
  Did CP/M sell for $180 because DR priced it that way, or because IBM priced it that way?
  - WalterBright 9y ago
    I read once (sorry, don't remember where) that DR priced it that way because CP/M utterly dominated the 8 bit market and felt CPM/86 had the brand name and the technical superiority to charge a higher price. The miscalculation is that IBM PC sales were mainly to first time users who had no history with CP/M, and (as I mentioned) the technical superiority of CPM/86 was not apparent.
    - jecel 9y ago
      The only "technical superiority" of CP/M that I can think of is having files associated with separate users, though I can't imagine anybody ever used this. The PIP command, copied from DEC OSes, was a lot more awkward than COPY in DOS. But a significant problem with CP/M was that if you swapped a floppy disk in a drive the system wouldn't notice it and things could get really messed up, so you had to remember to always control-c after changing disks. DOS would check, which reduced performance but was much more user friendly.
      - WalterBright 9y ago
        DEC had COPY on their PDP-10 operating system at least as far back as 1975 when I started using it. DOS clearly had a lineage going back through CPM to DEC. The CR-LF line endings also trace their way back to DEC.
- tzs 9y ago
  > Data I/O, the company I worked at [...] Hmmm...were you there when Data I/O was planning on acquiring Callan Data Systems? If so, what did you guys hear about the reason the acquisition did not go through? I was at Callan at the time as a Unix kernel hacker, and we technical people never heard any solid information on why that acquisition did not happen.
  - WalterBright 9y ago
    Sorry, I was a bottom tier grunt and not privy to any management decisions.

WalterBright 9y ago

When I bought my first PC, there was IBM PC-DOS and IBM CPM/86 at the store. DOS was $40, CPM/86 was $180 (if I recall correctly). I (and everyone else) bought DOS for that reason. Data I/O, the company I worked at, bought a few copies of CPM/86 and we tried it out. There were a few people who liked it, but most preferred DOS. Nobody could explain to me any reason to prefer CPM/86 - technical, practical, or price. CPM/86 had a shot. IBM sold both. CPM/86 lost fair and square.

int_19h 9y ago
Did CP/M sell for $180 because DR priced it that way, or because IBM priced it that way?
- WalterBright 9y ago
  I read once (sorry, don't remember where) that DR priced it that way because CP/M utterly dominated the 8 bit market and felt CPM/86 had the brand name and the technical superiority to charge a higher price. The miscalculation is that IBM PC sales were mainly to first time users who had no history with CP/M, and (as I mentioned) the technical superiority of CPM/86 was not apparent.
  - jecel 9y ago
    The only "technical superiority" of CP/M that I can think of is having files associated with separate users, though I can't imagine anybody ever used this. The PIP command, copied from DEC OSes, was a lot more awkward than COPY in DOS. But a significant problem with CP/M was that if you swapped a floppy disk in a drive the system wouldn't notice it and things could get really messed up, so you had to remember to always control-c after changing disks. DOS would check, which reduced performance but was much more user friendly.
    - WalterBright 9y ago
      DEC had COPY on their PDP-10 operating system at least as far back as 1975 when I started using it. DOS clearly had a lineage going back through CPM to DEC. The CR-LF line endings also trace their way back to DEC.
tzs 9y ago
> Data I/O, the company I worked at [...] Hmmm...were you there when Data I/O was planning on acquiring Callan Data Systems? If so, what did you guys hear about the reason the acquisition did not go through? I was at Callan at the time as a Unix kernel hacker, and we technical people never heard any solid information on why that acquisition did not happen.
- WalterBright 9y ago
  Sorry, I was a bottom tier grunt and not privy to any management decisions.