Bowmar 901B

The Bowmar 901B was the first "True-Pocket-Size" calculator based on components of the Texas Instruments company. This calculator uses both the original Klixon™ keypad and the TMS0103 Integrated circuit. There is no doubt that the display was manufactured by Bowmar, known as LED manufacturer. 
Compare this Bowmar 901B with the Mariner NRC7200 sporting displays from Monsanto.

Digging in the history of portable electronic calculators ? Don't miss the Sharp EL-8 and Rapidman 800.

Later with the Bowmar 901D a similar calculator with a 10 digit display was sold.

This calculator was sold under different labels, beside this Bowmar 901B it was popular as Commodore C110 and Craig 4501, too. A very similar design was introduced by Columbia with the Scientific. Don't miss the minirex 73, the eastern copy from GDR company RFT and the Heathkit IC-2009. The Litronix Checkmate looks similiar but is completely different.

If you are familiar with the Klixon™ keyboard, have a deeper look onto the following machines: All three calculators were manufactured by Texas Instruments and use this original keyboard:

Compare this 901B with later products like the MX-55.

Klixon™ is a trademark of Texas Instruments.

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

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