Texas Instruments TI-83 Parcus

Date of introduction:  2002 Display technology:  LCD dot matrix
New price:   Display size:  8 * 16 characters
Size:  7.2" x 3.2" x 0.85"    
Weight:  5.6 ounces Serial No:  2151010657
Batteries:  4*AAA + CR1620 (35mA) Date of manufacture:  mth 10 year 2002
AC-Adapter:   Origin of manufacture:  China (S)
Precision:  14 Integrated circuits:  CPU: Toshiba T6C79
 RAM: GM76C256
 Display: Toshiba T6A04A
Program steps:  28k Bytes Courtesy of:  Joerg Woerner

When Texas Instruments introduced with the TI-81 their first graphing calculator it made use of a standard 8-bit hardware architecture known from e.g. the TI-95 Procalc and FIA-10:

A 8-bit microprocessor of the Z80 family, a huge ROM of 128k Byte capacity, a RAM of 32k Byte size and a driver for the LCD display.

TI-83N_PCB.jpg (335395 Byte)The TI-83 Parcus introduced in 2000 is basically identical but streamlined the printed circuit board (PCB) to just 4 components:

Toshiba T6C79 - Application specific CPU, combines a Z80 core with an ASIC
MX-ROM - 256k Bytes Mask ROM for internal program storage
Hyundai GM76C256 - 32k Bytes S-RAM for user program and data
Toshiba T6A04A - display driver

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 approaches 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 the TI-83 Parcus the integration of the CPU into the ASIC.

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 ROM of this TI-83 Parcus was manufactured by Macronix International, the largest supplier of ROM products established in 1989 in Taiwan. 

RAM (Random Access Memory): The RAM is used as data memory and is used to store both variables, user programs and intermediate results. This TI-83 Parcus makes use of GM76C256 manufactured by Hyundai, Korea. The capacity of the memory is 32k Bytes.

TI-83N_Kbd.jpg (146814 Byte)TI-83N_COB.jpg (290585 Byte)DISPLAY: The Toshiba T6A04A 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 Parcus 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.

We prepared together with fellow collector Xavier Andréani a comprehensive comparison of entry level graphing calculators, to shed some light on the different specifications of the TI-82 and TI-83 / TI-83 Plus based products.

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 stylish TI-82 STATS introduced in France, the sibling TI-82 Parcus and the first edition of the TI-83.


TI-83_I0601_OS.jpg (42692 Byte) 1.10001

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


Information provided by and Xavier Andréani.

Exam acceptance:

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

horizontal rule

If you have additions to the above article please email:

© Joerg Woerner, April 26, 2008. No reprints without written permission.