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Mathatronics Mathatron 8-48M Model II Electronic Calculator

Mathatronics isn't a name that comes to mind for many folks today when asked to think of a maker of electronic calculators. The obvious choices always come up: Texas Instruments, Hewlett Packard, Casio, and Sharp. These "big four" of the calculator industry are the only really big names left in the industry anymore, along with a smattering of speciality companies, and very low-cost offshore manufacturers. Though the Mathatronics name isn't generally known, the company has a solid place in the early history of electronic calculators. Mathatronics' early calculators set many firsts in the infancy of the art.

Before delving into the specifics of the calculator in this exhibit, a bit of a history lesson is in order.

The idea for the Mathatron calculator was the brainchild of William Kahn, an electronics engineer who was frustrated by having to work with the slow and cumbersome electro-mechanical calculators of the day. Having worked on the design of first and second-generation computers at Datamatic (Honeywell's computer division), Kahn felt that many of the concepts of large computers could be scaled down to a small desktop-sized "personal" machine that would dramatically increase the productivity of people involved with performing complex mathematical operations as part of their work. Kahn worked in his spare time developing the ideas behind such a machine. After finishing up the design for Datamatic's H-800 computer (Honeywell's first transistorized computer), Kahn left Datamatic to go to work for Raytheon. Kahn had shared his ideas for a calculating machine with his former boss at Datamatic, Roy Reach, who was intrigued with the idea. At Raytheon, Kahn met David Shapiro, a bright electronics engineer who also shared enthusiasm for Kahn's calculator concept. In February of 1962, the three men quit their jobs, and set out on their own to form Mathatronics, Inc., with the goal of the company to turn the calculator concept into a commercial reality. The men pooled their own money to come up with $18,000 of startup funding, and managed to round up an additional $54,000 in capital from outside investors. They set up shop in Waltham, Massachusetts, and used the initial funding to develop a working prototype of the calculator. The prototype would be used to demonstrate the concepts of the calculator to Mathatronics' outside investors, who were granted options in the company shortly after it was formed. These options would mature 30 days after the first successful demonstration of the prototype, and could provide the company the next infusion of capital to turn the prototype into a production product.

The Model 8-48MII is an improvement over the original Mathatron calculators, the Model 4-24 and 8-48, by virtue of the addition of 'pre-programmed' functions that provided advanced mathematical, scientific, and statistical functions to the machines. There were two versions of the 8-48M. The first version used the rotary control knobs of the original Model 4-24 and 8-48, and added an additional rotary switch and button on the keyboard that provided access to a series of up to eleven "pre-programmed" functions. The second-generation 8-48MII involved changing the power switch, operating mode control, and program selection rotary switches to pushbutton switches. The first generation 8-48M shared the same "CPU" (main logic assembly) with the original Mathatron 8-48, with additional logic to provide the pre-programmed functions. The second generation 8-48MII utilized what was called the "Model II" logic unit, which incorporated some design changes to the logic unit to better integrate the pre-programmed functions into the operation of the machine, and handle pushbutton access to these functions rather than selection by a rotary switch.

The pre-programmed functions of the 8-48M were stored in a magnetic core read only memory (ROM), holding normal Mathatron program steps which would carry out the various functions. Because the ROM could hold a selection of programs for any type of calculation, there were a number of different machines (both versions I and II) with ROM programs that were targeted towards various specialized math applications. The 8-48M was targeted toward mathematical applications. The model 8-48S had pre-programmed functions applicable to statistics work. The model 8-48C provided pre-programmed functions for civil engineering calculations, and lastly, the model 8-48SC provided functions useful for scientific calculations.

The Mathatronics Mathatron calculators hold a very important place in electronic calculator history. When introduced in late 1963, the Mathatron was the first solid-state, desktop, printing, floating point, algebraic entry, programmable, stored-program electronic calculator. That's quite a mouthful, but these dramatic (for the time) distinctions make the Mathatron the first production example of a desktop "personal computer" that could be programmed to automatically carry out complex calculations. Olivetti's Programma 101 is historically recognized as being the first desktop "personal computer", but the Mathatron was shipped to its first paying customer (Woods Hole Oceanographic Institute) nearly a year before the Programma 101 was announced. The Olivetti machine can boast an important first, that of providing for offline storage of programs and data via a magnetic card -- a feature that made it possible to quickly change the program in the machine without having to type it in each time. This first, combined with Olivetti's already solid position in the business machine marketplace, allowed Olivetti's machine to simply receive more attention than the Mathatron, which cemented its place historically, even though the Mathatron was truly the first of its kind.

"Clamshell" design of the 8-48MII, logic unit on bottom, keyboard/magnetic core/power supply on top

Kahn, Reach, and Shapiro worked tirelessly (and without pay) through late 1962 to develop the working prototype. In early December, 1962, their genius and hard work was rewarded in the form of an operating prototype calculator. This prototype machine had the basic form factor and features of the production calculator, but was housed in a wooden cabinet. The prototype provided four memory registers and 24 steps of "learn mode" program storage. The machine had decision-making features, allowing conditional and unconditional branching, making iterative calculations feasable. It provided printed output in the form of a fast 'ticker-tape' style serial impact printer. It had a capacity of nine significant digits, with full floating decimal, and a two digit decimal exponent ranging from -42 to +58. The machine featured algebraic entry, meaning that problems would be entered on the keyboad just as they would be written on paper, with the machine following the rules of precedence and parentheses. The calculator automatically performed the four standard math functions, along with an automatic single-key square root function. No other desktop electronic calculating machine at the time, or for almost a year afterward, could even come close to the capabilities of this prototype calculator.

The prototype machine, designated the Mathatronics Mathatron Model 4-24, was succesfully demonstrated to Matatronics' investors a few weeks later, in late December of '62. The investors were amazed by the demonstration, and quickly offered to buy up their options in the company, immediately raising an additional $300,000 of capital to make the Mathatron a production reality.

In early 1963, Roy Reach started touring around the US with a non-functional wooden mockup of the machine, and examples of printed output from the prototype machine. While this was going on, Kahn and Shapiro were working on turning the prototype into a production reality. One of the places that Reach visited was Woods Hole Oceanographic Institute (WHOI). Based on the virtues of the paper tape output from the prototype machine, along with Reach's sales savvy, WHOI placed orders for two Mathatron 8-48 (double the memory and program step capacity of the prototype machine), without ever seeing a real calculator.

At the time the order was placed, a lot of details had yet to be worked out for the actual production calculator. WHOI wasn't daunted by having to wait for a production machine, as the calculator was exactly what they needed for ship-board calculations for their oceanographic research. At the time, there simply wasn't anything else that could come close to the capabilities of the Mathatron that would fit within the confines of a sea-going research vessel.

Mathatron 8-48MII "Top Plate Assembly"
Left: Keyboard Encoder
Right: Core Memory Arrays

In June of 1963, Friden had publically demonstrated their groundbreaking solid-state calculator, the Friden 130. The Model 130 is historically recognized as the first desktop solid-state electronic calculator. While a major accomplishment, the features of the Friden 130 paled in comparison to the capabilities of the Mathatronics machine. And, at around the same time of the 130's debut, Mathatronics had the first production Mathatron 8-48 ready to deliver to WHOI. Kahn and another Mathatronics engineer named Charles French, loaded the machine into Kahn's car, and set out for the roughly two hour drive to Woods Hole. Unfortunately, when the machine was powered up to show to the eager scientists at WHOI, it would't work. Some quick attempts were made at troubleshooting and repair, but these were unsuccessful. With their "tails between their legs", Kahn and French loaded the machine back into the car, and headed back to Waltham, determined to figure out what had gone wrong. A couple of weeks later, the problems had been identified and fixed. In early July of 1963, Kahn and French returned to WHOI with a fully operating machine. The folks at WHOI were enoumously satisfied with the machine, and arranged for it to be installed onboard one of their research vessels for immediate use. Shortly thereafter, the second production Mathatron 8-48 calculator was delivered to WHOI, where it was immediately sent with meet up with the same ship somewhere overseas.

Keyboard implementation detail: Keycap actuated micro-switches

Technically, it could be argued that the Mathatronics Mathatron calculator should take the historical credit from Friden as being the first solid-state desktop electronic calculator, but the Mathatron was not publically introduced until November, '63 while Friden's EC-130 was introduced in June. Both Friden and Mathatronics (and probably some others) had prototype calculators running in late '62, but from a historical perspetive, the formal public introduction of a calculator for sale seems to be the appropriate benchmark to use for determining who was first to market with a new technology.

At the same time that Mathatrhonics was working to get the WHOI order fulfilled, manufacturing capacity had ramped up, but the marketing effort had stalled somewhat. There were a few orders that had come in from other customers (MIT's Lincoln Lab and MITRE Corporation) as a result of Reach's low-buck marketing visits, but no concerted public marketing effort had yet been made. A decision was made to formally introduce and kick off the marketing campaign for the Mathatron at the NEREM trade show to be held in nearby Boston in November of '63.

Mathatronics "Model II" Logic Assembly

The NEREM show, along with other electronics trade shows where the Mathatron calculators were shown, were a big hit. By early 1964, orders began coming in at a good clip, and spirits were riding high. Mathatronics had made a place for itself at the high-end of the brand new electronic calculator marketplace.

Unique "bobbin wire-wrap" wiring method (US Patent 3,502,787)

Through 1964 and into 1965, the model 4-24 and 8-48 were good sellers. Mathatronics' engineering expertise went to work improving the original design, making minor changes to allow for the addition of external devices such as a teletype interace to allow a Teletype model ASR-33 to be connected to the calculator to provide better data printout capabilities, as well as development of a memory expansion unit that would provide additional program step and memory register storage. Another improvement was the addition of a read-only memory (ROM) that stored 'canned' programs for more advanced math operations such as trigonometric functions, logarithms, and exponential calculations. These changes all came together to become the first generation Mathatron 8-48M(Mathematics), 8-48C(Civil Engineering), 8-48SC(Scientific), and the 8-48S(Statistical) machines. These machines had a rotary switch on the front panel that allowed the desired math function to be selected, along with a keyboard button that caused the selected function to be executed. These "Version I" machines and peripherals were introduced in the fall of 1964.

While the Version I Mathatrons were successful, the rotary switch based controls proved to be a bit tedious in day to day use. A minor redesign of the main logic unit allowed better integration of the advanced math functions. The "Model II Logic Assembly", along with an improved keyboard interface circuit board, provided the logic necessary to allow the rotary switch mode and function selection controls to be replaced by individual keyboard pushbuttons. This design change made the advanced math functions provided in ROM much more accessible to the user, with each function having its own key on the keyboard. With this change, a single keypress would trigger the execution of the ROM program for the desired function. The calculator exhibited here is an example of a Version II Mathatron calculator. The Version II machines were introduced in the last half of 1965.

Ad for Barry Wright/Mathatronics' Mathatron 8-48MII, Circa mid-1966

Keep an eye on this preview exhibit for updates as they become available.

Text and images Copyright ©1997-2019, Rick Bensene.