Texas Instruments TI-2550 II

Date of introduction:  October 17, 1975 Display technology:  Fluorescent
New price:  $49.95 Display size:  8
Size:  5.8" x 3.2" x 1.3"
 147 x 81 x 32 mm3
Weight:  6.7 ounces, 190 grams Serial No:  208610
Batteries:  BP2 Date of manufacture:  wk 01 year 1976
AC-Adapter:  AC9130, AC9130A Origin of manufacture:  USA
Precision:   Integrated circuits:  TMS1071
Memories:  1    
Program steps:   Courtesy of:  Joerg Woerner
    Download manual:   (US: 2.8M Bytes)

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.

The TI-2550 II is featured in the Texas Instruments Deutschland GmbH leaflet ER-1976 dated 1976.

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If you have additions to the above article please email:

Joerg Woerner, December 5, 2001. No reprints without written permission.