DATAMATH CALCULATOR MUSEUM
|
DATAMATH CALCULATOR MUSEUM |
Texas Instruments TI-81
| Date of introduction: | October 1993 | Display technology: | LCD dot matrix |
| New price: | $110 | Display size: | 8 * 16 characters |
| Size: | 6.8" x 3.1" x 0.85" 172 x 80 x 21 mm3 |
||
| Weight: | 5.6 ounces, 168 grams | Serial No: | 20023247 |
| Batteries: | 4*AAA + CR1620 | Date of manufacture: | mth 08 year 1994 (F) |
| AC-Adapter: | Origin of manufacture: | Taiwan (I) | |
| Precision: | 13 | Integrated circuits: | CPU: Toshiba T84C00 ASIC: Toshiba TC14L010 ROM: LH5359©1993 RAM: SRM2264 Display: T6A04 |
| Memories: | 0-27 | ||
| Program steps: | 2,400 Bytes | Courtesy of: | Joerg Woerner |
Texas
Instruments changed in 1993, together with the introduction of the TI-82,
the design of the TI-81 slightly. Please notice the
position of the TI-logo, it moved from the upper right position to the upper
left of the screen.
From much higher interest to us are the design changes inside
the third series of the TI-81. Dismantling this calculator manufactured in
February 1994 reveals two major changes:
The
three display drivers (two T6A39
column drivers and one T6A40 row drivers) housed in huge Quad-Flat-Pack packages
of the original design were replaced by one tiny Toshiba T6A04
chip directly attached to the flexible printed
circuit board (Flex-PCB) of the LCD display.
Even
the main printed circuit board (PCB) was changed completely and looks identical to the PCB found
in the TI-82. Instead the Toshiba T6A43 - an application
specific Z80 controller - it accommodates now with the Toshiba T84C00 a standard Z80 CPU
with an additional ASIC Toshiba TC14L010 (1.0 micron C-MOS gate array with 1,000
usable gates). Learn more about the
Hardware Architecture of TI’s Graphing Calculators.
We recently learned that the major changes in the hardware design are not
correlated with the cosmetic changes. A fellow collector noticed identical
hardware in a TI-81 sporting the old design and manufactured in September 1993.
Texas Instruments changed in 1995 the design of the TI-81, TI-82 and TI-85 slightly, please notice the position of the TI-logo and the color of the type designator. Please find a detailed overview of the different hardware architectures of the TI-81 generations between 1990 and 1995 here.
ROM-Versions:
2.0V
You can check the ROM version of your TI-81 using the following key sequence and reading the number on your screen:
