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Texas Instruments PC-800 Printer

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
Weight:  50.8 ounces, 1,442 grams Serial No:  1235363
Batteries:   Date of manufacture:  wk 34 year 1982
AC-Adapter:  120 V or 240 V or DC Origin of manufacture:  USA (ATA)
Precision:   Integrated circuits:  CD8000B, 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.

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 manufactured by Texas Instruments in August 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, each.

The two microcontrollers with Custom Design Software CD8000 Revision B and CD8020 Revision A are not yet discovered, but we noticed that the CD8020 component uses already the final chip package while the CD8000 still uses a prototype package. 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 additional diodes with this PC-800 Printer compared to a PC-800 EVT (Engineering Validation Test) manufactured a few month earlier. 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!


 

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If you have additions to the above article please email: joerg@datamath.org.

Joerg Woerner, October 14, 2019. No reprints without written permission.