VEB Wilhelm Pieck MR 609

MR 609
MR 609

The MR 609 is a simple scientific calculator, fully made in all parts in the GDR.

It debuted in 1982 with the high price of 800 Mark (east), but the price dropped during its production time, which lasted till the late eighties. This calculator was also available under the model name "SR 1" ("Schulrechner"), a calculator for schools, which was subsidized by the GDR government.

case back
case back

Case and Keyboard

The MR 609 was designed and produced in the VEB Mikroelektronik "Wilhelm Pieck" in Mühlausen/GDR. It's a rugged construction with a plastic case and a full metal case back. Nevertheless, it's a very flat construction with a height of only 4mm.


Inside view, keyboard side
Inside view, keyboard side

The mainboard takes all the space in the case. On its top, it has got a hole, in which the CPU is inserted. This construction allows a very flat design.

The keyboard consists of individual keys, which are pressed against a rubber plate with conducting dots.

The LC display has got a plastic connector with lots of conducting stripes in it.


LED display
LED display

As a display, the MR 609 uses a contemporary LC display with a capacity of eight digits plus three additional indicators (minus, memory and error).


The CPU is the inhouse made U824G, a chip with 64 connectors on each of the four sides.

Calculating Capabilities

The MR 609 is capable of the standard calculations, adding memory and the usual triangle functions (sine, cosine, tangens and their arc-functions), precentage calculation, logrithmic and potential functions.


original GDR cells
original GDR cells

original GDR cells
original GDR cells

The power consumption of this calculator is so low, that on the specimen shown here, the original GDR-made AKA-SR44S-cells are still working, after more than 25 years!


Even when the MR 609 was on the rather lower end of scientific calculators in 1982, it is remarkable, that all parts were made inhouse. In western germany, this would have been impossible!

Technical data

ManufacturerVEB Mikroelektronik Wilhelm Pieck
ModelMR 609
Display8 digit LCD
Number of keys 34
Functions+-*/ SQR y^x SQRT sin cos tan ln lg % INV M
Entry logic (classificationALG (GD)
1 + 0.000 = 1.
0 / 0 = Error
sqrt(-1) = Error
sqr(sqrt(2)) = 2.
π = 3.1415927
Power supply 3V
Size13,3 x 6,9 x 1cm
Serial Number337029

Aufbau MR 609 (Robotron)