In November I purchased a calculator which had no manufacturer or model number on the front. The label on the back was BASIC SLIDE RULE with a serial number and the statement "Assembled in Mexico of U.S. and Foreign Parts". I could not find a similar calculator in the Ball/Flamm "Collector's Guide to Pocket Calculators".
On return to Florida I found that the calculator was mechanically very similar to my Sears Electronic Slide Rule. The Sears Electronic Slide Rule has more second functions for the keys and uses the right hand switch to select degrees or radians for the trig functions, while the BASIC SLIDE RULE offers fewer second functions and uses the right hand switch to select the display format. The Ball/Flamm book notes that the Sears Electronic Slide Rule was "... probably made by Rockwell, has interesting case and key style, similar case to the [Sears] M8". The Rockwell idea makes sense because both my BASIC SLIDE RULE and my Sears Electronic Slide Rule use a blue fluor display for the numerical value but use a red LED dot in the upper right hand corner of the display to indicate a negative value, and use a red LED dot in the upper left hand corner of the display to indicate overflow. That characteristic appeared in several early Rockwell calculators. I cannot read the label on the Sears Electronic Slide Rule but the Ball/Flamm book states that it was made in Mexico.
Does anyone know what entity marketed the BASIC SLIDE RULE ?