Additional Pictures 


The TI-2550 II sports two sliding switches.

The later TI-2550 III misses one of the switches.

The printed circit board (PCB) of the TI-2550 II
uses the TMS1071 single-chip calculator circuit
and a discrete power supply.

The later TI-2550 III with the cheaper TMS1043 driving
the Vacuum Fluorescent Display directly and an
additional DC/DC converter running from 1.2 Volt.

If you have additions to the above article please email:

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