Details about IBM's early 'scientific' computers

Rich Alderson RichA at
Wed Nov 15 15:28:16 CST 2017

From: Rick Bensene
Sent: Wednesday, November 15, 2017 11:59 AM

Grumpy Ol' Fred wrote:

>> Yes, 1968-1973 had time-sharing for personal computing, but not "personal
>> computers"

> While the definition of the term "personal computer" varies depending on who
> is using the term, these machines, and others like them, were designed to be
> used at a much more personal level than the large-scale mainframe machines
> housed in the glass-walled rooms where only "special" people were allowed
> anywhere near them.                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

This, like "Multics never got out of the lab", is a bogo-meme.  (Thanks, Neil!)

People did not *need* to get near the mainframes in order to do their jobs,
unlike the jobs for which the small systems (and you forgot the PDP-11 in your
list) were created.  Most programming on mainframes was special purpose, batch
oriented, data processing connected to accounting systems (GL/AP/AR/PR), and a
lot of the rest was high intensity engineering (where at this level even
physics is engineering) which needed lots of data handling for short runs.  In
the latter environment, time sharing was a big win, because multiple people had
access to the system for their work, without needing a bunch of underpowered
systems assigned to individuals.

I grew up in the mainframe world.[1]  I liked the idea of timesharing, but it
was not important to my job until the administrative DEC-20 was hooked up to
the Amdahl v7 via the HASP/RJE front end package for the -20.  Suddenly, the
EMACS editor which was a toy for me until then because a way to generate JCL
and PL/I for the mainframe where my responsibilities lay.  I did not need to
visit the computer room (several miles away) to do my job.

Later, I became a systems programmer on those mainframes, and had physical access
to the computers--but not because I was doing anything physical to the hardware.

I realize that most people here have an ongoing love affair with small systems.
I just want to point out that there were other ways to accomplish some really
interesting hacks.


[1] My first use of a minicomputer (a PDP-11 of small size, running RT-11) came
    in grad school, 10 years after I first started programming, in a
    linguistics class on "Production of Speech":  We turned the -11 into a
    speech synthesizer, for which it was perfectly suited.

Rich Alderson
Vintage Computing Sr. Systems Engineer
Living Computers: Museum + Labs
2245 1st Avenue S
Seattle, WA 98134

mailto:RichA at

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