Compucorp 322G Scientist

Description

Brand:	Compucorp
Model:	322G Scientist
Type:	Programmable Scientific Calculator
Picture:
Batteries:	D x 4
Lifetime:	Introduced: 1972 Terminated: unknown
Notes:	Compucorp 322G Scientist is a very early portable programmable scientific calculator. It was produced by Compucorp in the U.S.A. It was also available as the Sumlock-Compucorp, sold by the U.K based Sumlock Anita and as the Italy-based IME and others as well. It is quite big and heavy but it is also really a portable device. It has a carrying handle and can run on four big and heavy D-size batteries. Not for very long though for it is quite power hungry. It can also run on rechargeable batteries that can be charged using a power adapter. The fact that mine eats through its batteries might also be caused by it having old and leaky capacitors, I haven’t replaced them. It has a 12-digit amber fluorescent display which is really beautiful. When the batteries run out the display starts blinking. It is keystroke programmable and has 80 programming steps. There is no flow control but looping is possible. Programs are entered by sliding the RUN / LOAD slider to LOAD. Now enter the key sequences required. To finish the sequence end it by pressing the START STOP key. A sequence not finished will loop. It can store two separate programs, selectable using the PROG slider. To run a program, slide the slider to RUN, enter a value and press the START STOP key. The SET D.P. key (Digital Precision) is used to specify the numer of decimals displayed. Press it followed by pressing one of the number keys. It is sometimes peculiar how this calculator functions. For instance when squaring the number 2 (by pressing 2 × followed by repeatedly pressing =) the calculator will error out before using exponential notation. By not starting with the number 2 but by specifying 2 as an exponential number ( 2 EXP 0 1 × followed by repeatedly pressing =) this problem does not occur. Read some information relevant to this machine on this rskey.org page (link validated 2024-12-30) which is about one of its sibling models, the Compucorp 324G Scientist.

Personal Experience

Repair information:

When I got this calculator from a Dutch auction website and first tried it many of its keys were non-functional or would cause an error. When I opened up the calculator to try to find the cause, the most likely candidate was a 20 cm long Flat Flex cable made by TELEDYNE KIINETICS which was badly worn. Googling for a solution I came across Bob’s Calculators and Slide Rules and this page (link validated 2024-12-30) describing a similar issue with his Compucorp 322G Scientist. Bob created his own Flat Flex cable using adhesive-backed vinyl and cut strips of aluminum. I tried this myself, it took a good half day to create said cable and it actually worked. That is until I bended it just too often when reassembling the calculator. Tiny fractures appeared at both cable ends which were only protected by adhesive-backed vinyl (called Boeklon in The Netherlands) at one side. This might have been prevented by adding a solid bit of plastic at both ends but I decided not to spend another half a day on assembling a second home-built cable. After much more Googling I found a compatible cable, the FFC A/B 20 Pin 2.54Pitch Flachbandkabel Flat Flex Cable 20cm AWM. Bought it on eBay here (link validated 2024-12-30). Two Flat Flex cables with 20 pins that needed to be cut into two with only 14 pins.

After reassembly my Compucorp 322G Scientist is functional again! By the way to be on the safe side I bought two sets of these cables, so I can repair another one of them if I ever come across one or help someone else!

Peripherals

A power adapter.