Corvus 400

Date of introduction:  September 1974 Display technology:  LED-stick
New price:  $39.95 Display size:  8
Size:  5.0" x 3.0" x 0.9"    
Weight:  3.7 ounces Serial No:  400-016025
Batteries:  4*N cells Date of manufacture:  mth 12 year 1974
AC-Adapter:  6V DC, 75mA Origin of manufacture:  USA
Precision:  8 Integrated circuits:  Mostek MK50280A
Memories:  1    
Program steps:   Courtesy of:  Peter Muckermann

Corvus_400_1_PCB.jpg (73217 Byte)The keyboard design of the original Corvus 400 was changed within a few months from white to brown function keys. We are not sure if the changes of the LED display discovered with this Corvus 400 calculator manufactured in December 1974 correlate to the keyboard colors. Everything else seems to be identical to the first edition of the calculator, we still located a MK50280A single-chip calculator circuit and one digit driver circuit. Learn more about Mostek Calculator Integrated Circuits.

The later Corvus 400 makes use of the MK50282A calculator circuit instead the MK50280A chip. The differences are not yet discovered. Within some month the four unusual N-batteries were replaced with a standard 9V battery. Don't miss the Corvus 406

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Joerg Woerner, October 17, 2002. No reprints without written permission.