> DEC's mainframe at the time was the PDP-10 (36-bit word, 9-bit opcode,
> maximum memory 4M-36-bit-words), which typically cost many hundreds of
> thousands of dollars.  TOPS-10, the PDP-10 operating system,
> time-shared among lots of terminals.  I don't remember what its limit
> was, but I think 50 users at a time was not unusual.

> When I joined DEC's Small Systems Group, one member of the group was
> legendary -- Ritchie Lary.  PDP-8 development had to be done with a
> cross-assembler running on the PDP-10.  But the Small Systems Group
> didn't have enough PDP-8's for everyone to have one, so we each got a
> few hours a day on the real PDP-8 hardware.  It was extremely
> cumbersome to have to assemble your source code on the PDP-10, punch a
> paper tape of the binary, wait for your 2-4 hour time slot on the
> PDP-8 hardware, load the binary from paper tape, debug your code, and
> then have to go back to the PDP-10 and repeat the process if you
> needed to change anything in your code.  The story was that a year or
> two before I joined, Ritchie Lary realized that to do a standard edit,
> compile, and debug cycle all on the same machine, he'd need a
> single-user version of TOPS-10 running on the PDP-8.  So he went off
> and wrote it!  Other members of the group wrote the necessary
> utilities.  The editor (TECO) was translated,
> instruction-for-instruction, to the 8 instuction set.  Someone wrote a
> native PDP-8 assembler.  And thus was OS-8 born!  Lary's original name
> for it was the _*F*_ully _*U*_pward _*C*_ompatible _*KE*_yboard
> _*M*_onitor.  Of course, marketing couldn't call it FUCKEM, so they
> gave it a more respectable name.

> I know that if someone had suggested to me at that time that an OS
> that ran in Mega-words of 36-bit word memory could be implemented as a
> single-user verison in 8 Kilo-words of 12-bit word memory, with only
> 256 words resident, I'd have thought the idea was insane!  I've always
> felt that Lary's ability to see that such a thing could be done and go
> do it was true genius.

> Around 1973 or 1974, DEC's hardware engineers gave us a brand new, and
> quite innovative architecture, the PDP-11.  Its instruction set was
> nicely orthogonal so it was easy to learn, but was also quite
> powerful.  Its native post-increment and pre-decrement addressing
> modes inspired C's ++ and --.

> Our managers came to us and said that because OS-8 was doing so well,
> they need OS-8 reimplemented to run on the new PDP-11.  That's how
> RT-11 came into existence.

> Gary Kildall's CP/M started out as his own reimplementation of RT-11
> for the Intel 8080.  A few years later, Tim Paterson of Seattle
> Computer Products (SCP) wrote his own implementation of CP/M called
> QDOS (Quick and Dirty OS).  Bill Gates didn't write MS-DOS.  He simply
> bought rights to QDOS from SCP for $50,000 while keeping secret from
> SCP the fact that Microsoft's customer was IBM!  And that's how the
> whole chain of cloning and incremental improvement came to make a
> fortune for Gates under the name MS-DOS.

> For me, the lessons of this history are:

>    *

>      Good software usually involves someone with a brilliant insight
>      followed by a series of incremental improvements done by
>      individuals, either collaborating with one another or
>      unintentionally collaborating by copying and improving each
>      other's work.

>    *

>      Those who reap the rewards seldom have a significant hand in the
>      creation.  Instead they tend to be skilled publicists who make
>      dubious deals with naive programmers.

> I think some, but not all of this, applies to Steve Jobs too.  He was
> definitely quite skillful at promoting his company, their products,
> and himself.  He didn't invent the modern bitmapped graphics
> computer.  That work was done by people like Charles Thacker, Alan
> Kay, Douglas Engelbart, Robert Metcalfe, and others that most people
> have never heard of.  But I think Jobs had vision that allowed him to
> improve on their ideas while copying what they'd done, just as Kildall
> improved on what we'd done at DEC, and Paterson improved on what
> Kildall did.  In that regard, whatever other objections I may have had
> to how Jobs ran things, I have far more respect for him than for Gates.