Vintage 1974 Bowmar MX90 Calculator complete & works, box, charger, case & more

Description

This item is a Bowmar MX90 Electronic Calculator.  It is in very good condition and fully functional.  All the keys work fine and all have a consistent feel and sound.  The Bowmar 11 position (10 digits plus sign) "Optostic" LED display is in very good condition however the upper right segment of the right most digit is dimmer than the rest of the segments (see pictures).  The internal NiCad batteries have been replaced with three Tenergy 1000mAh NiCad cells.  The calculator is able to accept a full charge and power the calculator for several hours before a recharge is necessary.  It comes with the zippered carrying case which is in excellent condition inside and out.  The original Model B901-077-4 wall charger with the very odd polarity plug that fits perfectly into the calculator is included.  The charging port pins have been polished to a bright finish again to make good contact with the wall charger (see picture).  There is also the original box, instruction booklet, charging instruction card and cardboard charging insert which are all in excellent condition.  The instruction booklet has all of its pages with no tears, rips or writing inside.  Calculator was assembled in Mexico with serial #190963.  Case, wall charger and instructions are all made in the U.S.A.  All pictures are of the actual items you will receive.  Ships via USPS Priority mail with tracking.
Bowmar was the first manufacturer of small hand held calculators in the U.S.  Their first calculator design (the 901B) was just meant to showcase their "Optostic" red LED (light emitting diode) numeric display.  However, it was so impressive that they began producing it in large volume starting in 1971.  In the first few years of producing calculators, their revenue increased by over 20 times.  However, by the time the MX90 was released in 1974, competition between a then crowded field of competitors was taking its toll on Bowmar, especially with Texas Instruments who was both a supplier of parts to Bowmar as well as their competitor since they had realized a lot of money was to be made selling calculators too and not just the chips.  By 1976, Bowmar had filed for bankruptcy, their fall from dominance in the market just as fast as their earlier rise.  In 1974, the MX90 list price at one point was .99.  A year later in 1975, it was about a third of that.