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Texas Instruments TI-68

Date of introduction:  1989 Display technology:  LCD dot matrix
New price:  $65 Display size:  12 (8+2)
Size:  5.9" x 2.9" x 0.6"
 150 x 74 x 15 mm³
   
Weight:  3.3 ounces, 93 grams Serial No:  
Batteries:  CR2032 Date of manufacture:  wk 32 year 1990
AC-Adapter:   Origin of manufacture:  Italy
Precision:  13 Integrated circuits:  Toshiba T9948A
Memories:  0-55    
Program steps:  440-0 Courtesy of:  Roald Hendriks
    Download manual:   (US: 0.3 MByte)

Marketing guys called this calculator „Advanced Scientific“, others call it „almost Programmable“. At first glance the TI-68 seems to be a perfect calculator! A clear, alphanumeric display with a width of 12 digits, up to 55 memories or 440 programming steps and a calculation precision of 13 digits. Compared with the TI-60 you have only the limited programmability of a formula based machine and the maximum size of a program is only 79 steps. Another drawback is the overloaded keyboard with a 2nd, 3rd and ALPHA key. On the pros you get a lot of complex number functions and powerful equation solver. Nevertheless the TI-68 was a very successful calculator and produced from 1989 until 1999. 

TI-68_1_1.jpg (57545 Byte)To reduce the manufacturing costs of the calculator some mechanical and electrical changes were introduced with the TI-68 (1991) model. At first glance you recognize that the metal bezel of the first edition was replaced with a plastic bezel. 

TI-68_1_2.jpg (21387 Byte)TI-68_1_3.jpg (19696 Byte)The backside of the calculator reveals another methode of cost reduction. The screws to fix the housing parts together were replaced with a snap-fit construction.

TI-68_1_PCB.jpg (172394 Byte)Even the inside construction of the two calculators is different. Instead the screws to hold the printed ircuit board (PCB) in the bottom housing we notice the heat-stamped pins. The calculator circuit itself is identical with both models.

In 1995 part of the production of the TI-68 was shifted to Malaysia and later to China, compare the differences here. Roy, a satisfied user of the TI-68 reported recently that he owns a TI-68 manufactured in May 1997 proudly "Made in Italy". 

The TI-68 is one of the early calculators using the EOS or Equation Operating System compared to the original AOS system developed with the SR-52. The TI-68 lets you enter an expression into the entry line the same way as you would write it. You can move throught the entry line to review or edit any part of the expression before evaluating it. Most of the information about entering and editing applies both to equations and formulas. 

A more powerful calculator was introduced with the Galaxy 67, the TI-60X could be called the "TI-68 light".

As usual within the calculator line of Texas Instruments you'll find a similar Financial calculator. View the BA II PLUS.

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

TI-68? Read more about Chinese Lucky Numbers. Missing your TI-68? Think about the TI-30X Pro MultiView introduced in 2010 and its twin TI-36X Pro.

AOS™ and EOS™ are  trademarks of Texas Instruments.

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

© Joerg Woerner, May 2, 2003. No reprints without written permission.