Details:

The Diehl DSR18 is a high-end machine with lots of controls to determine how the machine operates. It is one of the rare machines with a real memory register. It not only allows to calculate an overall sum while performing adjacent calculations, but for further calculations the contents of the memory register can also be read back into either the result register (one dot) or the input register.

Less perfect is the implementation of multiplication. It’s only semi automatic and digits must be entered in a less natural reverse order.

The Marchants like the 10AFE multiply in the same way, but at choice digits can be entered from low to high or vice versa. They also operate fast enough to keep up with normal digit entry speeds. This DSR can’t.

While working on my machine it sometimes blocked while multiplying. I noticed the opening on the left bottom which gives access to an overal control reset (see photo above). It can be easily reached when the machine is in its normal operating position. Pulling it forward often got me out of the blocking condition.

Usage:

Addition/subtraction:

As usual using the “+” and “-” keys.

Multiplication:

Enter 1st number in the keyboard. Next use the most-left column to enter the digits of the second number. The second number must be entered in reversed order, i.e. from right to left.

Division

Enter the 1st number, push the ‘L’ key. Then enter the 2nd number and push both the ‘#o’ and “o” key..

Remark: The ‘L’ key resets register 1 first, the ‘V’ key does not.

Function of all keys, switches etc:

See the assets page of this machine

Click to view a full size picture (opens in a new tab)

Serial number:

Build in:

Functions:

Rotation speed:

Market-introduction:

Production until:

Price:

32 292

Ca. 1960

Addition, Subtraction, Semi Automatic Multiplication and Division

430 operations/min (To lower mechanical stress I’ve set it to 390)

1957

1961

DM 4250 in 1961 (Bron: BüromaschinenLexikon)

Mechanical Calculators |

Electronic Calculators |

Typewriters |