DATAMATH CALCULATOR MUSEUM
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
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
Display: Novatek NT7564H
|Program steps:||24k Bytes, 1M Bytes Flash ROM||Courtesy of:||Xavier Andréani|
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
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.
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.
5.1.0.0029 (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] 
Information provided by ticalc.org and Xavier Andréani.
If you have additions to the above article please email: firstname.lastname@example.org.
© Joerg Woerner, May 29, 2020. No reprints without written permission.