Old Calculator Museum Advertising & Documentation Archive
Sharp Compet 32 Model CS-32C Electronic Calculator Advertisement
Advertisement for the Sharp Compet 32 Model CS-32C Calculator Electronics Magazine, March 3, 1969
An advertisement for the CS-32C version of the Sharp Compet 32
electronic calculator, as well as two lesser stable-mates in Sharp's
line of calculators, the Compet 17 and
Compet 22.
When the Compet 32 calculator was first introduced in August of 1967, the
machine marked Sharp's highest-powered desktop calculator
to date. The machine provides a full 16 digits of capacity, has two
accumulator-style independent memory registers, and two-key automatic
square root, along with the usual four math functions. Along with being
the most powerful, it was also the smallest calculator that Sharp had
made, using advanced circuitry to shrink the machine down considerably
from earlier calculators in Sharp's lineup.
At the time the Compet 32 was introduced, the calculator represented
a new design paradigm for Hayakawa Electric (which was the name of the
company before it changed its name to Sharp Corporation in January of
1970). Earlier calculators made by the company utilized individual flip
flop-based registers, drove the Nixie Tube displays individually using
decoder/driver circuitry for each digit in the display, and used a
digit-at-a-time calculating method.
The Compet 32 switched to the use of a small magnetic core memory array for
storing the registers of the calculator, utilized multiplexed display
technology where only one decoder/driver circuit was shared by all of
the digits of the display. Multiplexing drives only one digit at
a time, with all of the digits each lit for a short amount of time before
switching to the next digit. This was done fast enough that the human
eye perceives all of the digits of the display lit at once. This method
saved a great many components by sharing one decoder driver circuit between
all of the digits of the display. Display multiplexing also fit well
with the next architectural difference between the Compet 32 and earlier
Sharp calculators, which is that calculation is done a single bit at
a time versus a digit at a time. This was another component-count reducing change, because
rather than having a full four-bit arithmetic unit, the arithmetic
unit only operated on one bit at a time. This was a bit slower, but saved
a lot of components. Along with these architectural changes, the
Compet 32 continued the use of small-scale bipolar integrated circuits
that began with the
Compet 31, further
reducing the component count needed to implement the logic of the
calculator. All of these things combined to allow the Compet 32 to
be dramatically smaller than Sharp's previous rather bulky calculators,
as well as reducing manufacturing complexity, increasing reliability,
and in the end, reducing the cost-to-manufacture. Some of the reduced
cost to make the machines which was passed
on to the consumer, with the rest improving Sharp's margin on sales of
the machine.
Especially in the late 1960's, it was not uncommon for calculator companies
to keep selling a machine for as long as possible in a hugely competitive
marketplace. The development cost of a new calculator design was very
expensive, so selling the machine for as long as possible allowed the
development cost to be amortized over the lifetime of the product. The longer
a given model of calculator was able to be sold into the market at a
competitive price and still provide a decent margin on each sale was key
to maintaining profitability. For this reason, calculator companies
would task their engineers to revisit the design of existing calculators
looking for ways to improve the design by making changes that reduce the
component count, fix minor issues that have been identified by service
statistics as common reliability problems, utilize newer technology
where available and effective in reducing manufacturing cost, and implementing
changes to the mechanical hardware to make the calculator easier to
assemble. The changes were made in such a way that they did not change
the look or features of the calculator in any substantive way, but either
allowed the calculator to remain price-competitive in the marketplace
for a longer period of time, or may have made minor changes to the calculator's
operation that were desirable from a user's perspective, such as adding
an indicator that lights when a memory register contains any number other
than zero(essentially a memory-in-use indicator) or adding support for
true negative numbers (versus tens-compliment representation).
In the case of the Sharp Compet 32, like all Sharp calculators, the initial
model of the calculator has an A suffix to the model number, e.g., the
initial Compet 32 calculator had a model number of CS-32A. The calculator
advertised here is the Compet 32 model CS-32C. Usually, revisions to
a given model involve moving to the next letter of the alphabet for
the model number suffix, but it appears in this case that Sharp jumped
from CS-32A to CS-32C without making a CS-32B model. At least as far as is
known at this writing, no model CS-32B Compet 32 calculators have been
found. If you happen to know of a Sharp Compet 32 Model CS-32B, please
click the EMail link above and let the museum curator know about it.
The museum does not yet have a Compet 32 Model CS-32A to compare with
the Model CS-32C that it currently has (but has not yet had an exhibit
created for it at this writing) in the collection, so it is not known
specifically what the differences are between the CS-32A and CS-32C, but
it is suspected that they involve refinement of the logic
design to reduce component count, with associated layout changes to the
circuit boards. There may also have been changes to the circuit boards
to make the boards easier or less-expensive to manufacture. It is also
likely that there were changes to the display drive circuitry, as it is
known that the original Compet 32 CS-32A display drivers had some
components that were under-rated for the voltages that the displays use,
which could have caused failures that were easily unavoidable by replacing
these components with parts that had higher voltage ratings. Other
changes could have been in the power supply circuitry to simply it as
well as potentially improving its design. Until the museum can get a
Sharp Compet 32 Model CS-32A for comparison purposes, the exact details
will remain unclear. If you have a Sharp Compet 32 Model CS-32A that
you would like to find a new home for, please consider contacting the
Old Calculator Museum.
This document is presented in embedded PDF. You may need to click above this
text, or refresh the page for image to show, depending on your browser.
If you don't have Adobe Acrobat Reader or some other form of PDF viewing
program, you may not be able to view this page.