Canon TP-8 Pocket Printer Repair

Released around 1982 by Canon, the Canon TP-8 pocket printer (sometimes referred as a palm printer or just The PocketPrinter) was advertised as a quiet and lightweight, yet versatile device. It was sold for about a year until its discontinuation in 1983. It usually would come with a few rolls of custom-made thermal printing paper, batteries (which may not last as long as the instruction manual states), and an AC adapter with a specialized DC plug.

The white plastic shell, which are in 2 halves, are held together by small internal tabs. The top half has all of the electrical components fastened to it by screws, which include the small rubber buttons and the plastic switches used for operating the calculator, as well as the 7-segment display and the thermal paper printing mechanism to view calculations. The bottom half holds a battery chamber with a sliding hatch, and next to the paper chamber, the specialized AC adapter port.

Original Advertised Price: $24.97

Operating Temperatures: 0°C-40°C (32°-104°)

Dimensions (WxDxH): 71mm x 175mm x 26mm (2-13/16" x 6-7/8" x 29/32")

Weight: 175g (6 oz.)

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Power Specs:

Power rating: DC 6V, 2.5W

Wall Adapter: Proprietary AD-4II, 8W

• Input: AC 120V, 60Hz
• Output: DC 4.5V, 600mA

Batteries: 4x 1.5 LR6 AA batteries (referred to as Penlight batteries in adverts and instructions)

Battery Life:

• Intermittent Use: Prints 1 roll w/ quality manganese, 2 rolls w/ alkaline manganese
• Continuous Use: Prints 2 rolls w/ quality manganese, 5 rolls w/ alkaline manganese

Operation Specs:

Operation Type: arithmetic

No. of functions: 8

• +, -, ×, ÷, ^, sqrt, %, bar graph

Logic: Algebraic

CPU: MOSTEK 6010L VLSI

Microprocessor: 2x Mitsubishi M58888P

Memory: 3 entries

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Display: 9-digit blue/teal 7-segment VFD

Paper printing:

Printer motor: Fuji electrochemical SM-30 stepper

Printing type: Thermal dot printer

Paper type: Coreless Canon Roll Paper TP38

Database Entries:

Basic TP-8 overview on calculator.org

Scrapbook TP-8 entry on CALCUSEUM

Detailed specs on MyCalcDB

Brief teardown overview by a french collector

YouTube Videos:

TP-8 Overview by Vintage Digits

TP-8 Refurbishing by Tech Tangents