Tektronix Model 21 Desktop Calculator
The Tektronix Model 21 was basically a MOS/LSI technology reimplementation
of the Cintra/Tektronix 909.
Tektronix acquired Cintra in May of 1971, and began selling the 909 under
the Tektronix brand. At around the same time, Tektronix began a program to
develop its own calculators. In July of 1973, Tek introduced both the
Model 21 and Model 31 calculators.
The Tek 21 was a basic scientific calculator with simple learn-mode
programmability and the ability to store and load programs on magnetic
strips. Tektronix did not find much success in the rapidly changing calculator
marketplace, and exited the market late in 1974. The Model 21 was not a
strong seller, leaving Tek with a large surplus of unsold machines which were
unceremoniously destroyed as a write-off. The Old Calculator Museum is
looking for any examples of the Tek 21, working or not, as well as any
documentation or sales literature.