Texas Instruments TI-83 (Engineering Sample)

The original TI-83, introduced in 1996, received after three years a slightly different look in response to the very positive reaction of the then new TI-73. 

From a technical point of view the TI-83 very similar to the revised TI-82 introduced in 1999, too. The main differences are the integration of the Z80 core and the supporting ASIC with into the Toshiba T6C79 Application Specific CPU. This high integrated chip found its way into the TI-82 Parcus and TI-83 Parcus, both introduced in 2001.  

Disassembling this TI-83 Engineering Sample manufactured in May 1998 reveals no big surprises. It makes use of just 4 main components on the printed circuit boards (PCB’s):  

CPU (Central processing Unit): The Toshiba T6C79 is a so-called Application Specific CPU and combines a Z80 core with an ASIC (Application Specific Integrated Circuit). You’ll find different approached within the graphing calculator line of Texas Instruments, sometimes the use of an individual CPU (e.g. Z80 and M68000) with a supporting ASIC or – like with this TI-83 the integration of the CPU into the ASIC. Learn more about the Hardware Architecture of TI’s Graphing Calculators.

ROM (Read Only Memory): The ROM contains the operating system of the calculator. The first products on the market used mask-programmable ROM, the program was stored already during the production of the Integrated Circuit. Later calculators changed to Flash ROM, a technology allowing the programming of the software during the final production stage of the calculator. With the TI-83 Plus and all later graphing calculators from Texas Instruments even the user was able to reprogram the operating system.

The TI883-03©1998 Mask ROM of this TI-83 was manufactured by Macronix International, the largest supplier of ROM products established in 1989 in Taiwan.

RAM (Random Access Memory): The Static RAM is used as data memory and is used to store both variables, user programs and intermediate results. This TI-83 makes use of W24258S manufactured by Winbond, Taiwan. The capacity of the memory is 32k Bytes.

DISPLAY: The Toshiba T6A04 is a driver for small-to-medium-sized dot matrix graphic LCD. It is compatible with Z80 based CPUs and drives displays with up to 120 columns and 64 rows. The display of the TI-83 is just 96 * 64, therefore only one display driver is necessary. The bare chip is mounted on a flexible piece of circuit board attached between the display and the main PCB.

A special "teacher version" called TI-83 VSC combines the standard TI-83 features with a port to connect to a ViewScreen panel via a cable. Placing the panel on the overhead projector enlarges the image of the handheld screen so that each student can follow along.

A serial port of the calculators allows the connection to the Calculator-Based Laboratory system CBL, its successor CBL 2, the Calculator-Based Ranger CBR and its successor CBR 2.

Don't miss the colorful slide cases developed for the TI-83 Plus, they fit on the 2^nd generation TI-83, too.

The design of the TI-83 changed during production slightly, don't miss the original TI-83.

ROM-Versions:

1.08000

You can check the ROM version of your TI-83 using the following key sequence and reading the number on your screen:

[MODE] [ALPHA] [S] JPEG_TI-83_OS.htm#1.08000

Information provided by ticalc.org and Xavier Andréani.

Exam acceptance:

The TI-83 is permitted (as of September 27, 2007) for use on SAT, ACT, PSAT and AP exams.

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

© Joerg Woerner, October 2, 2005. No reprints without written permission.