Selectric Typewriter conversions

From: Fred Cisin <cisin_at_xenosoft.com>
Date: Tue Feb 4 12:23:00 2003

> > Does anyone remember what was required to convert an IBM Selectric
> > Typewriter to a computer printer? I seem to recall a kit of some sort
> > was available, but my memory is
> > *really* hazy about that.

On Tue, 4 Feb 2003, Eric Smith wrote:
> There were two ways to do that.
> The more common method was to put a thing with one solenoid per key
> over the Selectric's keyboard. This had the advantage that no
> modification to the Selectric was required.

The two most popular ones of those were the Rochester Dynatyper (which had
an interface board with two edge connectors - one for plugging into Apple
][ bus, and other for TRS-80 model 1 expansion connector), and the KGS-80,
(which had a Centronics compatible parallel port input).

> The more clever (IMHO) mod was to attach seven solenoids to the
> Selectric between the keyboard encoding mechanism and the print
> mechanism, to directly control the tilt and rotate. And two more
> for the carriage return and paper advance. This has the advantage
> that you can still use it as a typewriter without having to attach
> and remove the solenoid box, and it's potentially less expensive
> since it takes nowhere near as many solenoids. I seem to recall
> that Don Lancaster wrote a do-it-yourself article about this
> approach.

I remember there being an outfit in Walnut Creek that sold a kit for
mounting under the keyboard of a selectric.

> Either way, though, you don't end up with a particularly great printer.
> The Selectric typewriters weren't meant to be pounded on continuously
> at anywhere near their full speed, since that wasn't how typewriters
> were used (even by *very* good typists).

Some (most?) selectrics were rated at a maximum of 14.8 characters per
second. That is oft cited for the reason for existence of the 150 baud
rate on many modems.
I knew one professional typist who could AVERAGE 150 wpm on an 8 hour
day! She could "wear out" a selectric during the "warranty" period.

> IBM made "I/O Selectrics," which had heavy-duty mechanisms intended
> for continuous output. Model numbers that come to mind are the
> 1052 and 753, though my memory regarding these seems more than a
> little fuzzy.
> There were also Selectric-based terminals like the 2741, which were
> AFAIK not quite as heavy-duty as the 1052, but still better than a
> typewriter.

And there were special dedicated heavy duty ones for cranking out dead
tree spam, that would permit storing a document, and pausing for a typist
to fill in blanks. "Dear ___, of all of the families living on ____
street, ..." That included the MTST ("Magnetic Tape Selectric
Typewriter") and later the MCSC ("Magnetic Card Selectric Typewriter").
I remember one fellow writing an early microcomputer mail merge program
that he wanted to call "the FULL ST", but nobody got the pun with MTST.

Sellam probably still has the service manual from my MTST.

> Trivia: although the Selectric typewriter wasn't introduced until
> 1962, the first production units were delivered to customers in 1961,
> as part of the operator console for the IBM 7030 Data Processing
> System (Stretch). Since it wasn't an announced product, all the
> publicity photos of Strech had a person, sign, or other item
> strategically placed to obstruct the view of the typewriter.

Trivia2: There were numerous type balls for the selectric, including APL!
Received on Tue Feb 04 2003 - 12:23:00 GMT