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Texas Instruments SR-56

Date of introduction:  May 21, 1976 Display technology:  LED-stick
New price:  $179.95, DM 598.00 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:  13757
Batteries:  BP1A Date of manufacture:  wk 32 year 1976
AC-Adapter:  AC9130A Origin of manufacture:  Italy
Precision:  12 Integrated circuits:  TMC0501, TMS0537, TMC0538, TMC0599
Memories:  10    
Program steps:  100 Courtesy of:  Joerg Woerner
Download leaflet:   (US: 7 573 kB) Download manuals:   (US: 14 692 kB)
  (US: 12 893 kB)

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 programm length from 224 steps to 100 steps. Main disadvantage was the lack of a permanent storage like a card reader or the continious memory of the later TI-58C.

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

SR-56_CMP.jpg (167136 Byte)There are two different versions of the calculator reported, one with and one without the word "Programmable" under the SR-56 logo.

SR-56_PCB.jpg (306488 Byte)The SR-56 uses like the SR-50, SR-51 and SR-52 the TMC0501 scalable calculator architecture. It is surrounded by the TMS0537 and TMC0538 SCOM (scanning read only memory) and the TMC0599 memory chip.

SR-56_IC.jpg (128608 Byte)According to Texas Instruments the SR-56 was introduced May 21, 1976 which is around week 20 of the year. Recently french collector Francis Martin discovered two SR-56 with production codes LTA1176 and LTA1276. Dismantling the calculators gave datecodes of the two SCOM's (scanning read only memories) of week 11 in the year 1976, too. This proofs that the SR-56 were manufactured already in March and we assume that Francis is the lucky owner of rare "pre-production run" calculators.

In the meantime Ken Kaplan revealed a production code LTA0876 and datecodes on the SCOM's of week 05 in the year 1976. 

SR-56_Late_IC.jpg (247576 Byte)Texas Instruments introduced on May 24, 1977 the famous calculator trio TI-57, TI-58 and TI-59 replacing both the SR-52 and SR-56. German collector Stephan Feinen discovered recently a SR-56 with a production code of 2477ACH - weeks after the introduction of the successors!

Don't miss a SR-56 manufactured in Brazil.



The SR-56 is featured in the Texas Instruments Incorporated bulletin CB-195A dated 1976 and in the Texas Instruments Deutschland GmbH leaflet ER-1976 dated 1976.

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.

SR-56 Database

Serial Number Origin Date code Logo Owner
006042 USA

LTA 0676

   Bill Kabelac
006468 USA LTA 0676   Bill Elliott
019040 USA LTA 1276   Carlos
028398 USA LTA 0876   Gilles Collas
028531 USA LTA 0876   Coy Lam
032022 USA LTA 4176   Bill Hastings
032705 USA LTA 4176   Palmer Hanson
044120 USA LTA 0876   Giovanni Legnani
046199 USA LTA 0876   Computer History Museum
046479 USA LTA 0876   Ken Kaplan
046644 USA LTA 0876   Clark Casale
051730 USA LTA 2076   Ben Davis
055273 USA LTA 3076   Wolfgang Kemper
056731 USA LTA 2076   Jack Crafchick
056955 USA LTA 2076   Gabriel Baum
060538 USA LTA 1276   R.J. Legman
060685 USA LTA 1276   John Versluys
065865 USA LTA 1276   George Nix
067219 USA LTA 4176   Al Paslow
069417 USA LTA 3276   Joerg Woerner
079905 USA LTA 2476   Jack Crafchick
080968 USA LTA 3076   Alain Gressier
083301 USA LTA 3076   Joerg Woerner
088033 USA LTA 3076   Claus Buchholz
090418 USA LTA 3776   Walter Roberson
094013 USA LTA 3176   Hugh Wilkinson
095984 USA LTA 3276   Randall Scheuerman
098184 USA LTA 3676   Glen Petersen
098537 USA LTA 3676   Computer History Museum
102519 USA LTA 3776 Programmable Bob Tessier
103493 USA LTA 3976   Lenny Tosto
114101 USA LTA 3576   Michael Shackelford
118534 USA LTA 3676   Paul Kowalski
118822 USA LTA 3676   Gavin Wickham
121400 USA LTA 3276 Programmable Joerg Woerner
131819 USA LTA 5176   Al Paslow
______ USA LTA 0577 Programmable Joerg Woerner
146169 USA LTA 4876   n.a.
146241 USA LTA 4976   Joerg Woerner
152051 USA LTA 0877 Programmable Joerg Woerner
154031 USA LTA 4576   S.Plavinski
154601 USA LTA 4676   Erik Polk
163274 USA LTA 0277 Programmable Jack Hummingbird
177154 USA LTA 0677   David Ribera
177390 USA LTA 0677   Zbynek Hak
177787 USA LTA 0677   Thomas Kapper
188872 USA LTA 0477 Programmable Joerg Woerner
190055 USA LTA 0277   Joerg Woerner
191156 USA LTA 0477   Lynda Charles Shelton
191372 USA LTA 0477   bennyboy6
          
051742 Brazil 5076 CIB    Joerg Woerner
          
9102216 Netherlands xxxx ACH   Luis Ametrans
9103776 Netherlands 1476 ACH   Tihomir Santek
9111387 Netherlands 2376 ACH   Josef Bém
9116613 Netherlands 4776 ACH   Doug
9117455 Netherlands 4876 ACH   Joerg Woerner
9119233 Netherlands 4376 ACH   Sture Bloom
9119742 Netherlands 4376 ACH   Joerg Woerner
9120647 Netherlands 4876 ACH   Joerg Woerner
9123166 Netherlands 4876 ACH   Thomas Ritschel
9______ Netherlands 1277 ACH   Hans Larson
9______ Netherlands 1777 ACH   Erich A. Gindl
9143748 Netherlands 1877 ACH   Zbynek Hak
9145454 Netherlands 1877 ACH   Thomas Gill
9147826 Netherlands 2277 ACH   Tom Pereira
91486xx Netherlands 1277 ACH   Miroslav Krob
9153225 Netherlands 1377 ACH   Aron Barman
9159914 Netherlands 1277 ACH   Thomas Gill
9______ Netherlands 2177 ACH   Gilles Collas
9______ Netherlands 2477 ACH   Stephan Feinen
9______ Netherlands 2477 ACH   Marc van Lemmen
9______ Netherlands 2477 ACH   Christoph Kraft
          
13035 Italy 3276 RCI   Marcus von Cube
13757 Italy 3276 RCI   Joerg Woerner
18150 Italy 4276 RCI   Zbynek Hak
19477 Italy 4076 RCI   Joerg Woerner
_____ Italy 4276 RCI   Varga Balázs
35794 Italy 4976 RCI   Audun Mathisen
51847 Italy 4976 RCI   Peter Engels
53938 Italy 4976 RCI   Joerg Woerner
54020 Italy 4976 RCI   Joerg Woerner
54135 Italy 4976 RCI   Thomas Kapper
55438 Italy 4976 RCI   Fedele Decandia
57913 Italy 4976 RCI   Bastian Schmelzer
59452 Italy 4976 RCI   Joerg Woerner
59728 Italy 4976 RCI   Ian Stirling
          

 

If you have additions to the above article please email: joerg@datamath.org.

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