Texas Instruments TI-84 Plus T

Date of introduction:  November 2015 Display technology:  LCD dot matrix
New price:    Display size:  8 * 16 characters
Size:  7.5" x 3.3" x 0.85"
 190 x 84 x 22 mm3
Weight:  7.4 ounces, 208 grams Serial No:  1015001729
Batteries:  4*AAA + SR44 (35mA) Date of manufacture:  mth 12 year 2015
AC-Adapter:   Origin of manufacture:  Philippines (L)
Precision:  14 Integrated circuits:  ASIC: TI REF 84PLCR/TA1
 Flash: MX29LV160
 Display: Novatek NT7564H
Program steps:  24k Bytes, 1M Bytes Flash ROM Courtesy of:  Xavier Andréani

Texas Instruments introduced in 2015 in the Netherlands with the TI-84 Plus T a modified version of the TI-84 Plus sold elsewhere adding a visual feedback LED for Press-to-Test and dropping Assembler support of the integrated Z80 CPU.

Dismantling this TI-84 Plus T manufactured in December 2015 by Kinpo Electronics, Inc. in the Philippines reveals a design very similar to the TI-84 Plus but adding a LED with a small light pipe for the visual Press-to-test feedback - known from the TI-82 Advanced released in 2015, too for France. We located on the printed circuit board (PCB) of the TI-84 Plus T three main components:

TI REF 84PLCR/TA1: Z80 microprocessor, RAM, USB-Port 
    and supporting logic
Macronix MX29LV800: 1M Bytes Flash ROM
Novatek NT7564H: Single-chip 64*120 pixel display driver

The picture on the right gives an enhanced view of the ASIC that clocks the internal Z80 microprocessor with 15 MHz and incorporates the RAM, USB-Port and logic. Learn more about the Hardware Architecture of TI’s Graphing Calculators. Please notice the smaller package of the new TI REF 84PLCR/TA1 ASIC compared with the previous TI REF 83PLUSB/TA2 or TI REF 84PLUSB/TA3 found in the TI-84 Plus family manufactured between 2004 and 2007.

Recently members of the Graphing Calculator Programming community under the lead of Xavier Andréani made a very interesting discovery:

All TI-84 Plus / S.E. with the TA2 or TA3 ASIC have access to 128k Bytes RAM.
All TI-84 Plus / S.E. with the TA1 ASIC have access to only 48k Bytes RAM using
    the same assembly commands.

This TI-84 Plus T manufactured in December 2015 makes use of one Macronix Flash ROM with 2M Bytes capacity, please notice that the otherwise identical TI-82 Advanced uses a Flash ROM with only 1M Bytes capacity.

The driver circuit of the LC-Display was traditionally manufactured by Toshiba for Texas Instruments' graphing calculators. This TI-84 Plus T manufactured in December 2015 shows with the Novatek NT7564H a one-by-one replacement. It is just a bare chip mounted on a flexible piece of circuit board attached between the display and the main PCB.

ROM-Versions: (actual in May 2020)

You can check the ROM version of your TI-84 Plus T using the following key sequence and reading the number on your screen:

[2nd] [MEM] [1]

Information provided by and Xavier Andréani.


horizontal rule

If you have additions to the above article please email:

© Joerg Woerner, May 29, 2020. No reprints without written permission.