Texas Instruments TI-92 Plus

Date of introduction:  April 22, 1999 Display technology:  LCD dot matrix
New price:  ($179.99 in 2003)  Display size:  12 lines by 40 char 
 128 * 240 pixels
Size:  4.7" x 8.2" x 1.2"    
Weight:  17.4 ounces Serial No:  V0702516
Batteries:  4*AA + CR2032 (35mA) Date of manufacture:  mth 10 year 1999 (A)
AC-Adapter:   Origin of manufacture:  Taiwan (I)
Precision:  14 Integrated circuits:  CPU: MC68EC000
 ASIC: TI-REF 200C040
 Flash: LH28F160
 RAM: 2*SRM20V100 
 Display: 3*T6B07, 2*T6B08
Program steps:  188k Bytes, 702k Bytes Flash-ROM Courtesy of:  Viktor T.Toth

This TI-92 Plus introduced together with the pocket-sized TI-89 was the third upgrade of the original TI-92

In a first step TI introduced with the TI-92 E module a language selectable Operating System and an additional 128k User memory.

In a second step the TI-92 Plus module replaced the pre-programmed Operating System with downloadable software.

With the TI-92 Plus engineers of Texas Instruments squeezed the former modules onto the main printed circuit board (PCB) of the calculator and made the former Expansion Port obsolete.

TI-92_PLUS_PCB.jpg (704089 Byte)The printed circuit board (PCB) of the TI-92 Plus looks similar to the original TI-92 PCB but we notice some changes:

Function TI-92 TI-92 Plus Comment
CPU SC414181 MC68EC000 +
ASIC 200C040
Application Specific CPU replaced by Standard CPU and ASIC.
ROM LH5388 LH28F160 1M*8 ROM replaced by 1M*16 Flash-ROM
RAM TC551001 2*SRM20V100 128k*8 RAM doubled to 256k*8
Column Driver 3*T6A39 3*T6B07 Replacement of obsolete parts
ROW Driver 2*T6A40 3*T6B08 Replacement of obsolete parts
Expansion Port available not available  

The main components of the TI-92 Plus manufactured in October 1999:

TI-92_PLUS_ASIC.jpg (168748 Byte)TI-92_PLUS_CPU.jpg (101593 Byte)CPU (Central processing Unit): The Motorola MC68EC000 - the original M68000 16/32-bit microprocessor introduced in 1979 - optimized for embedded applications is supported by the TI-REF 200C040 and replaces the costumized SC414181 solution if the TI-92. 

TI-92_PLUS_ROM.jpg (152607 Byte)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 strored 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 Flash-ROM LH28F160 of this TI-92 Plus was manufactured by Sharp, Japan. The capacity of the memory is 1M*16, or the equivalent of 2M Bytes.  

TI-92_PLUS_RAM.jpg (84099 Byte)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-92 Plus makes use of two SRM20V100 manufactured by EPSON, Japan. The capacity of the memory is 128k Bytes, each.

TI-92_PLUS_LCC.jpg (280516 Byte)DISPLAY: The TI-92 Plus uses - in opposite to the handheld graphing calculators from this era - display drivers in conventional packages. We noticed in this TI-92 Plus three T6B07 column drivers and two T6B08 row drivers manufactured by Toshiba, Japan. 

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. Texas Instruments announced June 2002 an optional full-sized QWERTY Keyboard for a more convenient entry of notes into the handhelds but it even matched the TI-92 Plus.

In addition to the handheld Graphing calculators features the TI-92 a direct connection port to either a ViewScreen panel or the TI-Presenter.

Within three years the TI-92 Plus was replaced with the Voyage 200 integrating identical hardware (beside the doubled Flash-ROM capacity) into a much smaller housing. This gave the original TI-92 a short lifetime of about 6 years but its genes will last much longer.


The original hardware of the TI-92 Plus is referred to as hardware version 2 and contains a 12 MHz processor. A regular TI-92 upgraded with the TI-92 Plus module is referred to as hardware version 1 and will not allow all applications, e.g. the clock functionality. You can check the HW version of your TI-92 Plus using the following key sequence and reading the number on your screen:  

[F1] [A]


TI-92_PLUS_OS.jpg (100691 Byte)1.00 (May 21, 1998)
1.01 (August 5, 1998)
1.05 (June 2, 1999)
2.01 (October 12, 1999)
2.03 (December 8, 1999)

2.04 (June 2000)
2.05 (May 11, 2000)
2.06 (not released)
2.07 (not released)
2.08 (July 29, 2002, recalled a
nd re-released February 20, 2003)
2.09 (March 27, 2003, actual in February 2008)

Advanced Mathematics Software v2.09  

You can check the ROM version of your TI-92 Plus using the following key sequence and reading the number on your screen:

[F1] [A]

Information provided by and Xavier Andréani.

Exam acceptance:

Since the TI-92 Series and Voyage 200 feature a QWERTY keyboard they are not allowed on ACT, SAT, PSAT and AP exams.

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© Joerg Woerner, December 5, 2001. No reprints without written permission.