Texas Instruments TI Programmable 57

Date of introduction:  May 24, 1977 Display technology:  LED-stick
New price:  $79.95, £49.95
 $40.00 (October, 1981)
Display size:  8 + 2
Size:  5.8" x 3.1" x 1.4"
 148 x 78 x 36 mm3
Weight:  6.4 ounces, 180 grams Serial No:  1246799
Batteries:  BP6, BP7 Date of manufacture:  wk 32 year 1977
AC-Adapter:  AC9131, AC9132 Origin of manufacture:  USA
Precision:  11 Integrated circuits:  TMC1501
Memories:  8    
Program steps:  50 Courtesy of:  Joerg Woerner
Download leaflet:   (US: 2.2 MByte) Download manual:   (DE: 13.1 MByte)

Introduced together with the TI-58 and TI-59 the TI-57 represented the low budget programmable calculator of that epoch and replaced the SR-56. Unbelievable that this powerful calculator made use of the one-chip approach of the SR-40 calculator. 

TI-57_PCB.jpg (43171 Byte)A sales brochure of 1977 says: "The key to its value is a remarkable advance in integrated circuit technology - a single MOS/LSI chip with the equivalent capacity of 30,000 transistors". Well, today the guys of TI integrate millions and millions of transistor on one chip.

A novel step was the squeezing of key entries into program code, the time before the memory hold the key codes. This technique allowed up to 3 key entries (i.e. INV-2nd-sin) to be compressed into one program step. Sure that marketing sold a calculator with 50 memory places as a calculator with 150 program steps!

Please read this interesting comment from Anders Persson: "However, it was actually possible to pack up to four keystrokes in one step, not only three. An instruction like INV-2nd-Prd-4 would still fit in one step (code -39 4). Admittedly, not many instructions took four keystrokes - perhaps this is the only one...". 

If you are interested in the calculating accuracy of scientific calculators don't miss the Calculator forensics.

Find a nice collection of program listings for the TI-57 on Laurent Bonnin's website.

Early in production (about wk 36 year 1977) TI changed the battery pack and the related connector and charger from the SR-51-II style to the TI-55 style. The battery packs are not compatible, don't use a BP6 with a AC9132 charger !

Simply by comparing the designation of the integrated circuits of the upper line "Majestic" calculators, you'll get the all members of this family:

TMC1501    TI-57 
TMC1502    MBA
TMC1503    TI-55

TI-57_1.jpg (49925 Byte)Later in production the metallized TI logo was replaced with an unmetallized. This gives in total 3 different US versions. View here the TI-57 w/o chrome. Finally we should add an early TI-57 assembled in Italy with different styling.

The TI-57 was sold under the label of Radio Shack as EC-4000 and in Hungary as Híradástechnika PTK-1050.  

The calculator was available till 1982.

The TI Programmable 57 is featured in the Texas Instruments Incorporated bulletins CL-274 and CL-283 dated 1977.

Find here an excerpt from the Texas Instruments Incorporated leaflet CL-199J dated 1981:

TI Programmable 57

The self-teaching programming system for student and professionals.

Eight multi-use memories provide addressable memory locations to store and recall data. Powerful program memory stores 50 fully merged steps (up to 150 key-strokes). Once a program is built, it can be executed repeatedly by supplying new sets of variables. Computer-like programming functions help solve repetitive problems quickly and accurately.
It’s also a powerful super slide rule calculator. AC adapter/charger and carrying case included.
Making Tracks into Programming. Takes you into the power and fun of programming right away, with step-by-step instructions and examples.

© Texas Instruments, 1981


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