Printed Resources

Below are a some selected references on calculators I have found to be particularly interesting that have a hardware flavor to them. This list is by no means all inclusive, and does not include service manuals, calculator applications books and articles, user/owner guides, buyer's guides, or other publications of interest to most calculator collectors.


R. P. Haviland, The "Compulator" Book (1977).
This is a project book where Mr. Haviland builds circuits to interface calculator chips to a Teletype and to a punched paper tape reader, among other things. The book lists the pinouts and keyboard matrix for several then common calculator chips and discusses techniques for exploiting unused features on a few of these chips. Like most books published by TAB BOOKS, this book is full of typographical errors which limit the reader's confidence in the accuracy of the material presented.

David L. Heiserman, Miniprocessors: From Calculators to Computers (1977).
In this project book, Mr. Heiserman leads the reader through three main projects: building a calculator using the MM5738 or MM5760, adding an MM5765 programmer, and finally building a programmer using TTL chips and 2102 RAM chips with more program capacity than the MM5765. Like the MM5765, this larger programmer does not possess any capability for conditional testing, branching or looping. Again, like most TAB books, the typographical errors and obvious omissions from diagrams erode the reader's confidence in the accuracy of the material presented.

Derivation and Tabulation Associates, Inc., Digital Integrated Circuit D.A.T.A. Book, Edition 5 (1979); Digital Integrated Circuit D.A.T.A. Book, Volume 17, Book 7 (August 1980); Digital & Consumer I.C.'s Discontinued Devices, Volume 28, Book 15 (June 1983).
These books are compilations of device data from numerous manufacturers - however, there are some conspicuous omissions. These books were published primarily to aid designers in the preliminary selection of components. They are composed of several sections, including part number indexes, functional indexes, logic diagrams and/or IC pin out drawings, and package outline drawings. From a hobbyist's perspective, these books provide far less information than is usually desired, but the information they provide is better than nothing. These books are part of a large set covering many categories of devices published over many years. The above volumes represent a random selection that happened to avoid the dumpster, survived the ravages of time, and contained some calculator IC information.

MOSTEK Corp., Integrated Circuit Guide (August 1974).
This data book provides technical specifications for numerous chips, including seven calculator chips, example circuits using these calculator chips, and detailed operating instructions for calculators incorporating these chips.

National Semiconductor Corp., MOS Integrated Circuits (April 1974).
National Semiconductor, Inc., MOS/LSI Databook (1977).
Like most data books, besides the technical specifications of the chip, there are examples of circuits using the chip, and detailed operating instructions for using a calculator incorporating that chip. Many of the calculator schematics presented appear to be those of actual calculators produced by National Semiconductor, Inc. Other sections of the data book provide specifications on the various display driver chips and LED displays they produced.

H. Edward Roberts, Electronic Calculators (1974).
Mr. Roberts was the head of Micro Instrumentation and Telemetry Systems, Inc. (MITS), an early manufacturer of calculators and personal computers. This book provides a broad coverage of the technologies of electronic calculators through the time the book was published. Included are schematics and narrative which can aid in the understanding and repair of electronic calculators.

Magazine Articles

W. L. Green, IC Pocket Calculator, Radio-Electronics, May 1972, at 40.
A construction article for Alpha Research Corporation's Americal-8 calculator. The calculator uses an "ARC-840" chip, which looks suspiciously like a Texas Instruments TMS1802. This construction article contains significantly less information than is typically encountered in a construction article in an electronics magazine. For example, conspicuously absent was any meaningful discussion about necessary display drivers. The display and driver circuitry must have been contained on a daughter board which was not pictured and only vaguely discussed in the article. That said, this is a very early article about building a calculator using an LSI "calculator on a chip."

Patrick N. Godding, Calculators How To Keep Them Running, Radio-Electronics, Aug. 1973, at 33. This article looks like an abbreviated version of the theory and service portions of Roberts' Electronic Calculators, which is not surprising given that Godding was a program manager at MITS.

Don Lancaster, Understanding Calculator IC's, [sic] Radio-Electronics, Jul. 1974, at 38. This article discusses operation of early calculator chips along with explainations and simplified schematics of display drivers and keyboards.

Mike May, How the Computer Got Into Your Pocket, Invention & Technology, Spring 2000, at 47. A captivating article on Jack Kilby and Jerry Merryman's invention and development of the pocket calculator.

Eugene W. McWhorter, The Small Electronic Calculator, Scientific American, Mar. 1976, at 88. The cover illustration shows a portion of the keyboard of an HP-65. The article describes the operation of a hypothetical 8-digit LED calculator.

Martin Meyer, Build An Under-$90 Scientific Calculator, Popular Electronics, Jan. 1975, at 53. Construction article for what looks like a Melcor SC-535 scientific calculator. This issue also introduces the MITS Altair 8800 microcomputer kit, making this magazine particularly difficult/expensive to locate.

Martin Meyer, Build The 'Senior Scientist' Calculator, Popular Electronics, Oct. 1975, at 33. Construction article for what looks like a Melcor scientific calculator.

Martin Meyer, Now You Can Build A Scientific Programmable Calculator, Popular Electronics, May 1976, at 36. Construction article for an unrecognized model (Melcor?) of programmable scientific calculator.

Donald Shapiro, How To Add Functions To Simple Hand Calculators, Popular Electronics, Sept. 1975, at 38. Provides instructions on accessing the memory, constant, and percent function of the MM5738, found in some Novus 850 calculators. (Note that many Novus 850s only contained the MM5737, which had no additional features.)

Howard F. Stearns, Add 4 Functions to Novus 850, Radio Electronics, Dec. 1976, at 55. Provides instructions on accessing the memory, constant, percent function, and battery-saving display blanking capability of the Novus 850 if it contained an MM5738. It was dumb luck that Stearns did not sever important circuit traces in the keyboard by drilling holes through the keyboard where he did to add his buttons.

Finding These Books and Magazine Articles

Most of these magazine articles should be available at the public library of any major city. If you are lucky, the library still has bound copies of the magazines. If you are not quite as lucky, the magazines will be available on microfilm. Photocopies from the bound magazines will be cheaper and give you better control over image quality than prints from microfilm.

Many of the books may still be available at your public library. But act quickly, many of these books are now old enough that they are being discarded by the libraries. For example, some of the above books are still on the shelf at the Fort Worth Public Library, but they have been removed from circulation at the Dallas Public Library. Finding these magazines and books to purchase is a lot like obtaining an old calculator. You can be patient and scour flea markets, garage sales, and used book stores, or you can try to find it on-line and pay a premium price.


Last updated September 3, 2006