Radio Shack EC-450  
Written by Accutron on 2017-02-24  

The Radio Shack EC-450 is a rare rebranded variant of the Bowmar MX100 Scientific Brain. Introduced in 1974, the MX-100 was Bowmar's first scientific calculator, built upon a Rockwell A4001 single-chip calculator and a Bowmar Opto-Stic eight digit LED display. As with most scientific calculators based on a Rockwell chip, the transcendental accuracy of the MX-100 / EC-450 is unimpressive, generating a forensic result (arcsin (arccos (arctan (tan (cos (sin (9)))))) of 10.4382. Still, this is significantly better than the results produced by some other Rockwell-based machines.

The EC-450 was introduced in 1975 at a price of $129.95, making it the first scientific calculator sold by Radio Shack, and also the most expensive calculator ever sold by Radio Shack. While the original MX-100 is housed in a black plastic case, the EC-450 has an unusual turquoise-colored case.

Bowmar MX100 Manual (PDF)


Radio Shack EC-450 scientific calculator.


EC-450 calculator, internal construction. Note the Rockwell A4001 calculator chip and Bowmar Opto-Stic display.

This article is part of the [Electronic Calculators] exhibit.

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