DATAMATH CALCULATOR MUSEUM
Texas Instruments TI-82 (Engineering Sample)
|Date of introduction:||(August 1993||Display technology:||LCD dot matrix|
|New price:||Display size:||8 * 16 characters|
|Size:||6.8" x 3.1" x 0.85"|
|Weight:||5.6 ounces||Serial No:|
|Batteries:||4*AAA + CR1620 (35mA)||Date of manufacture:||mth 06 year 1993|
|AC-Adapter:||Origin of manufacture:||Taiwan (I)|
|Precision:||14||Integrated circuits:|| CPU: Toshiba T84C00
ASIC: Toshiba TC14L010
Display: Toshiba T6A04
|Program steps:||28k Bytes||Courtesy of:||Joerg Woerner|
TI-82 was manufactured in or around June 1993 and seems to be a very early
engineering sample. Dismantling the calculator - lacking both serial number and
date code - reveals a little surprise. Instead of the
Sharp LH531 Mask ROM found in later products, a Toshiba TC541001AF OTP ROM (One Time Programmable ROM) uses its real estate on the printed circuit
Mask ROM, as the name suggests, refer to a kind of ROM (Read Only Memory) whose contents are programmed by the chip manufacturer. Main advantage of Mask ROM is its cost per component, while main disadvantages are both long lead times and the high costs of design errors. It was in the late 80s and the 90s common practice to use rather expensive user-programmable memories, for instance OTP ROM, till the software has finalized. (We know about 12 different ROM-Versions of the TI-82...).
else is identical with the later TI-82 sporting the
LH531 Mask ROM, even the
Toshiba T6A04 driver circuit of the LC-Display was used in the design. Learn more about the
Hardware Architecture of TI’s Graphing Calculators.
You can check the ROM version of your TI-82
using the following key sequence and reading the number on your screen:
[MODE] [ALPHA] [S]
Information provided by ticalc.org
and Xavier Andréani.
The TI-82 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: email@example.com.
© Joerg Woerner, February 6, 2009. No reprints without written permission.