DATAMATH CALCULATOR MUSEUM
Texas Instruments PC-800 Printer (EVT)
|Date of introduction:|| Never
(Announced: May 1982)
|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:|| CD8000B, CD8020A, SN77203,
|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 CD8000 and CD8020, a SN77203 Voltage
Controller chip and three ULN2002A arrays with seven NPN Darlington transistors,
The two microcontrollers with Custom Design Software CD8000 Revision A and CD 8020 Revision A are not yet discovered, but we noticed that both components 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.
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: firstname.lastname@example.org.
© Joerg Woerner, October 14, 2019. No reprints without written permission.