On Fri, Nov 6, 2020 at 5:58 PM Greg 'groggy' Lehey <grog(a)lemis.com>
wrote:
My memory is hazy, but I thought that the daisy wheel
printers I knew
(Qume Sprint\5) also had proportional spacing.
I never used that brand. Xerox (which was the main USA supplier as a pure
typewriter to compete with IBM's Selectric 'ball' units) were definitely
fixed width. People started to hack the Xerox units to add access to
serial interface and Xerox made it standard or maybe an option as
somepoint. IIRC it was somebody like Ollivetti that originally did the
daisywheel and Xerox licensed it and they definitely were the primary
player here. But by the late 70s, early 80's, there were a number of
manufacturers of them.
My memory was with the maybe circa 74/75 timeframe, Xerox unit (but it
might have been one of the others) was that the original unit had a serial
port for diagnostics/maintenance which allowed access to the on-board
microprocessor (which might have been a 4-bit TI chip IIRC - same used in
some early 'Simon' games). Somebody figured out how to hack it and the
schematics/description was available. I remember we hacked one of the
units in the EE dept. But by the late 1970's the serial interface was a
first class part of the unit, which made them different from IBM Selectrics
which did not have an easy to access serial interface, even though IBM used
the printer mechanism from the Selectric as the guts of the console for the
360 which I think was called a 2150 but the bits in my brain on that are
extremely stale.
I ran into significant
problems with early MS-DOS based formatting software because it made
(frequently incorrect) assumptions about character widths.
Greg
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