MELCOR Model 380

Date of introduction:  1973 Display technology:  LED Optostick
New price:  $100 Display size:  8
Size:  6.0" x 3.1 x 1.00"
 152 x 80 x 25 mm3
Weight:  5.0 ounces, 142 grams 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 their 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 their manufacturing of calculators and consequently changed their perspective for Bowmar and Melcor from component manufacturing to 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 MX55 and Sears Digi·Matic 8.

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