Additional Pictures 


The sales box of a Western Auto 66-4987-5 "Citation" sold in Winter 1977 in the US.

This Western Auto 66-4987-5 "Citation" was manufactured in October 1977 by
Texas Instruments in Midland, TX (Date code 4177 MTA week 41 year 1977).

The 66-4987-5 "Citation" is powered by a 9V alkaline battery.

The 66-4987-5 "Citation" manufactured in October 1977 in Lubbock, TX
with the rear part of its housing removed.

The printed circuit board (PCB) of the featured 66-4987-5 "Citation" is centered
around a TMC0923 single-chip calculator circuit hidden under the VF-Display.

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If you have additions to the above article please email:

Joerg Woerner, July 6, 2021. No reprints without written permission.