Texas Instruments TI-20

Date of introduction:  1979 Display technology:  LCD
New price:  $33 Display size:  8 (5 + 2)
Size:  5.3" x 2.9" x 0.35"
 134 x 74 x 9 mm3
Weight:  2.9 ounces, 82 grams Serial No:  
Batteries:  2*LR43 Date of manufacture:  wk 41 year 1980
AC-Adapter:   Origin of manufacture:  Italy
Precision:  11 Integrated circuits:  TP0326
Memories:  1    
Program steps:   Courtesy of:  Stefan Klaes

The TI-20 repeated an approach "invented" two years ago. Just like the lean TI-15 based on a fully loaded TI-30, this rare TI-20 is based on the TI-38

First we should recall the TI-38. This odd calculator based on the TI-35 and added some conversion functions instead of the removed statistical capabilties. 
And the TI-20 removed just this conversion functions ! What you get is the simplest member of all the slimline calculators.

Simply by comparing the designation of the integrated circuits of the calculators you'll get the first members of the slimline family:

TP0320    (CD3201) TI Investment Analyst 
TP0320    (CD3202) TI-30-II 
TP0321    TI-50
TP0322    TI-Business Analyst-II
TP0323    TI-53
TP0324    TI-35
TP0326    TI-38 and TI-20

TI-20_2.jpg (41492 Byte)Dismantling the TI-20 reveals a small surprise: The mold of the housing is identical to the TI-38 and the keyplate covers three empty spaces for additional keys.

TI-20_IC.jpg (42077 Byte)Even the keyboard holds the full array of 40 keys in 8 rows by 5 keys.

TI-20_1.jpg (75353 Byte)One owner of the rare TI-20 on the right discovered the hidden functions borrowed from the TI-38 and simply drilled three holes into the metal faceplate above the keyboard. 



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Joerg Woerner, January 6, 2002. No reprints without written permission.