Bowmar MX55

Date of introduction:  1974 Display technology:  LED Optostic
New price:  $89.95 (September 1974)
 $39.95 (November 1974)
Display size:  9
Size:  6.0" x 3.1" x 1.3"    
Weight:  9 ounces Serial No:  221391
Batteries:  3*AA Date of manufacture:  year 1974
AC-Adapter:   Origin of manufacture:  USA
Precision:  8 Integrated circuits:  WD LC1552
Program steps:   Courtesy of:  Joerg Woerner

The Bowmar MX55 was introduced more than two years after the famous Bowmar 901B. A lot of things happened in the meantime. The relationship between the competitors Bowmar, Ali and Texas Instruments wasn't the best (read more here) and you may notice it:

The keyboard looks like a Klixon™ keyboard manufactured by TI but was another design.
The calculator chip inside was from the independent supplier Western Digital.
Actually a LC1552B was used here, a chip supporting a 4-key memory. And this in a calculator without any memory!

MX55_1.jpg (38308 Byte)Compare it with the Montgomery Ward P8M or the Radio Shack EC-300 using an identical chip. New York based company Melcor made similar experiences, don't miss the Melcor Model 380.

Don't miss the similar looking but yet completely different Sears
Digi·matic 8.

Bowmar Instruments was one of the first casualties of the Calculator Wars and filed in 1976 for bankruptcy. Don't miss a mystery calculator with the Bowmar brand introduced in 1977!

Klixon™ is a trademark of Texas Instruments.

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© Joerg Woerner, December 5, 2001. No reprints without written permission.