The Commodore GL-986R is a vintage arithmetic calculator that offers 8 digits of precision and operates using algebraic logic. Released in 1974, this calculator provides basic yet reliable functionality for everyday calculations.
Manufactured by Commodore Japan Ltd., the GL-986R is a product of Japanese engineering, known for its quality and durability. The calculator features a 7-digit green Vacuum Fluorescent Display (VFD), with an additional possible eighth digit for indicating negative numbers or errors. This display type was popular in the 1970s for its bright and clear readability.
The calculator’s power source is a pair of AA-sized sealed rechargeable batteries, providing 3V DC. It also accepts an adapter through a socket located on the right side of the device. The adapter specifications are 0.2A with a 2mm plug and center positive polarity.
The Commodore GL-986R’s design is characterized by a three-piece black and silver spray-painted matte plastic case. The keyboard surround is sculpted, with the keys exhibiting a ‘squishy’ yet positive feel. The keyboard features bold, easy-to-use keys in the typical red, white, and blue color scheme of the era. The top section of the front is made of green, translucent matte plastic with a sloping clear window that serves as the display filter. A black-painted Commodore logo metallic label sits in its own recess, adding a touch of branding to the device.
In terms of functionality, the GL-986R offers six basic functions:
- Standard four arithmetic functions (addition, subtraction, multiplication, and division)
- Percentage calculations
- Square calculations
- Register exchange
The calculator’s dimensions are approximately 75mm x 140mm x 28mm (width, height, depth), and it weighs 124 grams excluding batteries. This compact size makes it portable and convenient for use in various settings.
The internal components of the Commodore GL-986R include:
- 1 x CPU: Western Digital LC1552-B 7446 (week 46 of 1974) 40 pin DIL, 0.6″ width
- 1 x 8-digit single round tube VFD display
- 2 x transistors
- 9 x diodes
- 6 x capacitors
- 2 x SIL resistor arrays
- 4 x resistors
- 1 x transformer
The calculator’s construction consists of two main boards: the keyboard board and the main CPU board. The keyboard board is fixed to the front with 12 screws and features numerous link wires. It connects to the main CPU board via a 14-way ribbon cable. Disassembly of the device involves removing two screws from the back of the case and gently squeezing the silver plastic sides to separate the back. The adapter socket must be loosened to lift the main CPU board.
The Commodore GL-986R is a typical member of the early Green Line series but represents a very basic model within that range. Despite its simplicity, it remains a notable example of early calculator technology, offering a glimpse into the evolution of personal computing devices.
