Friden 1150 Introduction Note
Electronics, February 19, 1968
A brief note announcing Friden's new
1150 printing
electronic calculator. While the Friden 1150 was not really
remarkable from the standpoint of features, it was rather remarkable
as it, at least as is known today, was the first printing electronic
calculator with its logic fully implemented using integrated circuits.
Friden carried forward the counter-based stack (RPN) architecture from
it's first-generation discrete transistor-based
EC-130 and
EC-132 electronic calculators,
but worked with Texas Instruments (TI) to implement the three
counters using three custom-made medium-scale TTL integrated circuits, one
for each counter circuit. The remainder of the 1150's logic was implemented
using TI's small-scale DTL and TTL integrated circuits. The only
discrete component circuitry in the machine was in the power
supply, drive circuitry for the printing system, and the write driver/
read amplifier for the magnetostrictive delay line used to store
the calculator's working registers.
Friden also developed its own rather unique printing mechanism
that utilized a moving carriage containing a print wheel with the
digits zero through nine, decimal point, and operation symbols
embossed on its circumference that spun at 3,600 RPM.
The symbols on the print wheel were inked by a special roller
that would transfer ink from a special ink cartridge. A single hammer
that moved with the carriage, but positioned behind the paper, would
fire just as a desired symbol would be positioned on the print wheel
so that the paper would instantly press against the embossed symbol,
causing it to be printed on the paper. The carriage moves right to left
across the width of the paper to allow all of the necessary symbols to be
printed at the rate of 37 characters per second.
See the
Old Calculator Museum's
exhibit on the
Friden 1152
for information on slightly later programmable version of the 1150 that used
the same technologies.
