Texas Instruments TI-2550 II
The name gives you a first idea of this calculator: It is the successor of the TI-2550, a wedge shaped basic calculator.
TI-2550_2_1.jpg (33781 Byte)The housing used for the TI-2550 II is identically to the SR-16
II,
the difference is the keyplate and the underlying keyboard frame. The TI-2550 II
uses two sliding switches and a green Vacuum Fluorescent Display, a rare
combination in TI's calculator history.
TI-2550_2_2.jpg (82731 Byte)The
TMS1071 discovered
in this calculator was the first LSI MOS
chip of the TMS1000
family using integrated display drivers, The TMS1001 found in the SR-16
used external drivers in conjunction with a Light Emitted Diode display.
The
TI-2550 II uses a battery pack BP2 with
only two rechargeable AA-sized NiCd batteries compared to the three cells used in
the original BP1/BP1A
pack.
This wonderful calculator was quickly replaced by the TI-2550
III,
a keyboard without a [+/-] key was not too useful.
A similar calculator chip was used with the innovative Canon MD-8 sporting a multi-line display.
Don't miss the TI-2550 II for the vision impaired people, the Schoenherr Braillotron 2550 II.
If you have additions to the above article please email: joerg@datamath.org.
ゥ Joerg Woerner, December 5, 2001. No reprints without written permission.