AKA: 8-U, ELECTRONIC CALCULATOR, AKA (Label): CASIO-8U, Product number (P/N): 8U (8-U),
Keywords/Tags: 8U (8-U) | ELECTRONIC CALCULATOR
Date of intro: ~1973, Origin: Japan (List), Dimensions: 180x115x50mm, Weight: 410g,
Power: 7.5V: (AA x5) + Adaptor, Adaptor: CASIO_adaptors: ADP2A,
Display: Type = Display (VFD) (List), Digits = 8+1,
Number of keys: 17, #Key-Red: 2, #Key-White: 15,
Keyboard Array (Rows x Columns): 04x05,
Decimal switch: [4-2-0-F], Miscellaneous switch: [K-OFF],
Classification: / Desktop with Display,
Featuring: Logic-technology: VLSI (Very Large Scale Integration), calculator-on-a-Chip,
Related with: (Docu_Articles): 197402: Le Guide Pratique Des Calculatrices de Poche; CASIO_docu: (Instr.) 8U; CASIO_docu: (Broch.) 8U: The new Casio-8U...; CASIO_docu: M10003437D (Broch.) 8U,
Main Components: CASIO: 8J1A,
Original Equipment Manufacturer : CASIO: 8U (List of all Export-OEM-models from CASIO), Resemblance with: REMINGTON: 803C,
Known Serial-numbers: 529867 | 597176 (List of all S/Ns from CASIO)
Initial Cost Price: 23800 JPY (€ 192,78), Collector value: 7.5/10,
Info: DUDEK Emil:
Interesting early CASIO that tries to bridge the gap between a desktop and handheld machine. As it will just fit in the hand, is battery powered and has a carry strap on the case it is probably best to call this a transportable.
The original cover is white soft plastic with a top/side/bottom (with a little bit of the remaining side) zip and integrated carry strap. It has Casio embossed on the front and Made in Japan on the back.
As you would expect, the RPN logic is archaic with lack of recovery. However, the pseudo fixed decimal bug is a surprise on a switched decimal calculator.
Boards:
The main board (8J-1(A) ) sits loosely on top of the keyboard assembly, and is joined by a bunch of 14 colored wires from a connecting block. The keyboard has four of its own capacitors.
Logic comments:
The [C] button is used to clear last entry of a number and the [AC] is used to clear the whole calculator.
Overflow on number input is suppressed, typing in a nine digit number ignores the ninth digit.
An overflow error shows zero result and an ‘E’ in the far left (ninth) digit, negative or positive and is not recoverable.
Divide by zero results in zero and an ‘E’ in the far left (ninth) digit which is also not recoverable.
There is switched constant on multiply and divide only.
The logic is Semi-RPN: to calculate 4-5 key in [4][+=][5][-=] to give ‘-1’
Negative numbers are flagged by a ‘-‘ sign in the far left (ninth) digit thereby allowing full eight digit negative numbers.
The decimal notation is switched between floating (F) and fixed 0,2 and 4 digits.
It suffers from the pseudo fixed decimal bug: switch to floating mode (F) and key in [1][+=][0][.][0][0][0][+=] to give ‘1.000’, which will remain a three digit fixed decimal until more places are needed.
Internet: Link-1: LEDUDU, Link-2: CASIO CALCULATOR COLLECTORS