Bohn Contex 55
Bohn Contex 55

Details:

Compared to other machines this was a very cheap calculator.  To allow for the low price some concessions  were done to functionality as well as the design.  Unlike most other machines there is no display of entered digits and multiplication is only half-automatic.

Internally parts are light and mostly punched out of steel plate.  Still, they appear to be reliable.


Usage:

Addition/subtraction:   

As usual, using the “+” and “-” keys.  Results appear in the lower register. The upper register is not used.


Multiplication:

Enter the first number. Push the “X” key. Enter the second number starting with the least significant digit.

Results appear in the lower register. The upper register is not used.


Division:

Enter the first number. Push the “DIV I” key.  Enter the second number. Push the “DIV II” key.

Division now starts.  Results appear in the upper register. The lower register shows the residual value.


Function of some keys, switches etc:

Calculator InfoBohn Contex 55  front viewBohn Contex 55  side viewBohn Contex 55  side viewBohn Contex 55  bottom viewBohn Contex 55  rear view

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Serial number:

Build in:

Functions:

Rotation speed:

Market-introduction:

Production until:

Price:


493 058 403

ca 1970

Addition, Subtraction, Half-automatic Multiplication, Automatic Division

?

1968

ca. 1972

Ca. DM. 1090,- in 1968 (Source:  Büromaschinen Lexikon)

Repair information & pictures of internals Video Assets: adverts, brochures, etc