Old Calculator Web Museum Advertising Archive
Sharp Compet 30 (CS-30B)
Advertisement for Sharp Compet 30 (CS-30B), circa June, 1967.
Thanks to Mr. Takaharu Yoshida for providing the scan of this advertisement
The Sharp Compet 30 (CS-30B) is an update to original version of this
machine, the CS-30A. The CS-30A was introduced in February of 1967 as
a reduced cost version of Sharp's first silicon trasistor-based
desktop calculator, the Compet 20.
The B version of the Compet 30 appears to have been introduced sometime
in the Spring of 1967, shortly after the introduction of Sharp's first
machine to use Integrated Circuits, the
reclusive Compet 31 (CS-31A), which
debuted in February of 1967. The CS-30B benefitted from some design changes
that made the machine easier to use than the A version, and (in at least
the few known surviving examples) leveraged IC
technology to simplify the design. The CS-30A used all-transistor
circuitry, while it appears that the CS-30B used small-scale integrated
circuit technology in its control circuitry. The CS-30B also added two
indicators at the
left end of the display; an error indicator that lit red when an overflow
occurred, and another indicator that lit yellow to indicate that the
memory register contained non-zero content.
With that said, there is some confusion in the community of calculator
historians between the Compet 30 CS-30B, and the Compet 31 (CS-31A).
The two machines appear to be identical in appearance and features. At
this time there is no known example of a Compet 31 in existence to use
to compare with the CS-30B. It could be that
the CS-30B and the CS-31A are in fact the same machine. Or, perhaps the
CS-31A was a first step, using a small number of IC's, with the CS-30B
(which clearly has the logic sequencing board filled with ICs) further
extending the use of integrated circuits. Until a CS-31A can be found,
this mystery will remain.