DATAMATH  CALCULATOR  MUSEUM

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*LR44 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

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

First we should remember the TI-38. This odd calculator was based on the TI-35 and added some conversion functions for the removed statistical capabilities. 
And the TI-20 dropped these conversion functions! The result is the least capable member of all the slimline calculator series.

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. 

 

 



horizontal rule

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

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