Texas Instruments SR-56 Programmable

Date of introduction:  1976 Display technology:  LED-stick
New price:  $139 Display size:  10 + 2
Size:  5.8" x 3.2" x 1.3"
 147 x 81 x 32 mm3
Weight:  8.5 ounces, 240 grams Serial No:  152051
Batteries:  BP1A Date of manufacture:  wk 08 year 1977
AC-Adapter:  AC9130A Origin of manufacture:  USA (LTA)
Precision:  12/13 Integrated circuits:  TMC0501, TMC0537, TMC0538. TMC0599
Memories:  10    
Program steps:  100 Courtesy of:  Joerg Woerner
    Download manual:   (US: 15.0M Bytes)
  (US: 13.1M Bytes)
  (US: 26.8M Bytes)

Introduced only few month after the SR-52 programmable, the SR-56 was it's small brother. The housing looked identical to the SR-51A, only the LRN-key gave you an idea of it's programmability. Compared to the SR-52 it uses only one instead of two memory-chips (the TMC0599), this reduced the possible program length from 224 steps to 100 steps. Main disadvantage was the lack of a permanent storage like a card reader or the continuous memory of the later TI-58C.

This calculator works with both the PC-100 and PC-100A printer cradle. 

There are two different versions of the calculator reported, one with and one without the word "Programmable" under the SR-56 logo.

Fellow collectors - if you own a SR-56 please report us the serial number and date code on the back of the calculator for our SR-56 Database.

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If you have additions to the above article please email:

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