Additional Pictures 


The leading TXI- designation on the label of the Montogomery Ward
P8F calculator reveals the manufacturer: Texas Instruments.

The printed circuit board (PCB) of the Montgomery Ward TXI-8644A
is used with the P8F and P8P calculator. 
More important is the number etched in the PCB: 13-04-709-504.

The small display board carries on the backside a similar 
number starting with the 13-04-709 code

The front of the display board finally gives an important link:
The Texas Instruments logo identifies the manufacturer of
calculator with 13-04-709 numbers. And we know a lot of them.

If you have additions to the above article please email:

Joerg Woerner, February 26, 2003. No reprints without written permission.