Additional Pictures 


This early TI-81 was manufactured in Taiwan but lacks any additional information, for instance the
Date code. Please notice the missing space for the backup battery.  

The PCB (printed circuit board) of the TI-81 manufactured early 
in 1990 looks different from the later calculators.

The main components of the TI-81: Toshiba T6A49 Application Specific CPU, unknown 1990 ROM and Toshiba TC5565A RAM. All Integrated Circuits of the calculator were manufactured not later than May 1990.

This early TI-81 graphing calculator makes use of three display drivers :
Two T7778A column drivers and one T7900 row driver.

If you have additions to the above article please email:

Joerg Woerner, January 27, 2009. No reprints without written permission.