Product number (P/N): 438,
Keywords/Tags: 438
Date of intro: ~1976, Dimensions: 125x72x20mm, Weight: 80g,
Power: 9V + Adaptor,
Display: Type = Display (LED) (List), Digits = 8+1,
Number of keys: 24, #Key-Black: 11, #Key-Orange: 2, #Key-White: 11,
Miscellaneous switch: [(ArrowRight)-ON],
Classification: / Pocket,
Featuring: Procent, Logic-technology: VLSI (Very Large Scale Integration), calculator-on-a-Chip, Memories: 1,
Related with: SOVRIN_docu: (Instr.) 438,
Main Components: (Unknown manufacturer): SPL0062A,
Serie-members: SOVRIN: 438 (version-1) (Black/Silver); SOVRIN: 438 (version-2) (Brown/Silver),
Known Serial-numbers: 863690 (List of all S/Ns from SOVRIN)
Collector value: 7.5/10,
Courtesy of: CALCUSEUM (Serge DEVIDTS),
Info: DUDEK Emil:
Cheap and cheerful calculator that has awful keys and a very limited viewing display (more than most LEDs).
No information even in the manual as to where this was made - typical of the cut-throat boom years with minimum components.
The original case is brown soft plastic with an open top.
The logic is let down by seven digit negative numbers and the pseudo fixed decimal bug.
Boards:
The keyboard assembly is fixed to the front via four screws and the main board (SPL0062) sits loose on top, face down.
They are joined by a 12-way ribbon cable.
Construction:
Held together by internal lugs only be careful not to damage this calculator if trying to open it. I found the best way was to lever the rear section away at the top and then progress down the sides.
The rear section will then come away.
Logic comments:
The [CE] key is used to cancel an entry whilst [C] clears the whole calculator.
Input overflow is suppressed inputting an ninth digit is ignored.
Negative numbers are shown with a ‘-‘ in the immediate left hand digit but as there is no ninth digit to travel into you are limited to seven digit negative numbers.
There is an automatic constant on all four functions.
The change sign function can be used in mid number entry.
Divide by zero shows a flashing ‘0’” in the far right (first) digit and is recoverable using [CE].
Overflow shows the result flashing and is recoverable using [CE]
There is no indication of memory storage - you have to remember it.
Internet: Link-1: VINTAGE TECHNOLOGY