Popular Electronics 1/1975: An under $90 Scientific Calculator

[Didier Lachieze]

The ICs are the MOS MCS 2525 & MCS 2526 (used also on the Commodore SR 36 & 1400 and other calculators at that time), the calculator described in this article is the Melcor 535, I have one as well as the two Commodore.

Two others similar articles have been published in Popular Electronics:

• Martin Meyer, Build The 'Senior Scientist' Calculator, Popular Electronics, Oct. 1975, p. 33 which describes how to build a calculator similar to the Melcor 655 which was sold as a kit.
• Martin Meyer, Now You Can Build A Scientific Programmable Calculator, Popular Electronics, May 1976, p. 36. This document includes at the beginning the article "Here Are The New Programmable Calculators"