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MELCOR Model 380

Date of introduction:  1973 Display technology:  LED Optostick
New price:  $100 Display size:  8
Size:  6.0" x 3.1" x 0.9"    
Weight:  5 ounces Serial No:  745888
Batteries:  9V Date of manufacture:  mth 07 year 1974
AC-Adapter:   Origin of manufacture:  USA
Precision:  8 Integrated circuits:  MOS MCS2521
Memories:  1    
Program steps:   Courtesy of:  Joerg Woerner

If we trace back the history of Melcor we locate the rare Mariner NRC 7200 as starting point of calculator business. The NRC 7200 was introduced already in December, 1971 and looks similar to the Bowmar 901B. Both designs used mainly technology and components from Texas Instruments, e.g. the calculator chip, keyboard, display drivers and even the display. In 1972 TI started the manufacturing of calculators itself and changed for Bowmar and Melcor from component manufacturing to a strong competitor. As a logical result a lot of "TI-free" calculators appeared. This Model 380 uses:

Keyboard technology from Ramsgate
A calculator chip from MOS Technology
A display manufactured by Bowmar
Display drivers made by ITT
 

Melcor380_PCB.jpg (207389 Byte)Compare this assembly with a Bowmar MX-55 and Sears Digi·Matic 8.

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If you have additions to the above article please email: joerg@datamath.org.

© Joerg Woerner, May 23, 2002. No reprints without written permission.