DATAMATH CALCULATOR MUSEUM
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DATAMATH CALCULATOR MUSEUM |
Texas Instruments PC-800 Printer (EVT)
| Date of introduction: | Never (Announced: May 1982) |
Display technology: | |
| New price: | MSRP: $185.00 | Display size: | |
| Size: | 6.5" x 10.0" x 2.7" 165 x 254 x 68 mm3 |
Printer technology: | Thermal TP-xxxxx |
| Weight: | 50.8 ounces, 1,442 grams | Serial No: | |
| Batteries: | Date of manufacture: | wk 14 year 1982 | |
| AC-Adapter: | 120 V or 240 V or DC | Origin of manufacture: | USA (ATA) |
| Precision: | Integrated circuits: | TMS1000/CD8000B,
TMS1300/CD8020A,
SN77203, LM393P, 3xULN2002A |
|
| Memories: | |||
| Program steps: | Courtesy of: | Joerg Woerner |
The
PC-800 Printer is a dot-matrix thermal printer designed for use with the
TI-88 Programmable. It connects to the TI-88 through a 2-pin
Peripheral I/O connector. A second Peripheral I/O connector on the back of the
PC-800 allows to connect another device like the CA-800
Cassette Interface to the TI-88.
Please notice that this PC-800 EVT (Engineering Validation Test) still uses a prototype housing with unfinished surfaces and a different color schema for the buttons and switches.
Printer Control of TI-88 Programmable:
| • Print the contents of the display at any time • Print alphanumeric prompts, operating instructions, and messages • Print program input and output • Print the contents of program or data memory • Print all labels used in a program • Print OP code and flag definitions, calculator settings, nd alpha entry positions • Print tracings of keyboard calculations and program execution showing each function executed with its result |
The PC-800 printer operates by moving an electronic print-head across a special heat-sensitive paper. Characters are formed on the paper from small dots produced by heated elements on the print-head.
Dismantling this PC-800
from an early EVT (Engineering Validation Test) manufactured by Texas Instruments
around April 1982 in their Abilene, Texas
facility, reveals a design with a complexity similar to the
PC-100C and PC-200
printers utilizing two microcontrollers
TMS1000/CD8000 and TMS1300/CD8020, a
SN77203 Voltage
Controller chip and three ULN2002A arrays with seven NPN Darlington transistors,
each.
The two microcontrollers with Custom Design Software
TMS1000/CD8000 Revision
A and
TMS1300/CD 8020 Revision A are in earl stages of their evolution, they still use prototype chip packages. The SN77203 is known from the
TI-88 Schematics Diagram, it converts
a single-cell battery (1.2 Volts - 1.5 Volts) to two independent power supplies,
one adjustable for the LC-Display through a Serial I/O pin and one fixed for the
main electronics.
Please
notice the missing diodes with this PC-800 Printer compared to a PC-800 PVT
(Production Validation Test) manufactured a few month later in August 1982. Learn more about
similar modifications discovered with the TI-88 PVT 2
(Production Validation Test 2).
The
PC-800 Printer can be operated by either an integrated AC adapter with 120/240
Volts (fixe-mounted power cord) or an external DC adapter (connector on the rear
next to the two Peripheral I/O connectors.
Printer paper:
The thermal paper used with this printer (Kanzaki Paper
KPB-53Z-48 1.97" wide and 85 Feet length) was discontinued long time ago.
Don't connect a CA-800 Cassette Interface or a PC-800 Printer to TI-88 calculators without the Diode-Modification!
If you have additions to the above article please email: joerg@datamath.org.
© Joerg Woerner, October 14, 2019. No reprints without written permission.