Elektronika 4-71b

"Calculator Elektronika 4-71B (working, you should push "C" after you switch it off to 220V (by the way, the Russian standard is 220V 50Hz, hope the same values can be found at electricity net in Sydney). It is impossible to know when and where was it produced, it seems to be at least 20 years old. It is rather hard (~400-500 g) and big but can calculate only +, -, ÷, x and % (may be square root, but I am not sure)."

- Igor Sokalski

The 4-71b opened up is very difficult to see any markings at all; the board screws are welded shut with glue I don't want to break. I did spot a "75" buried under a blob of glue, and in front of that handwritten 05, making it most probably a 1975 calculator.

This is a beautiful alien machine! I love it. Size is 23cm x 11cm x 4-5cm (horizontal format). fluorescent green display 8 digits, LOWER LEFT of horizontal unit. The most impressive thing is that its 9 segment (YES, NINE) display. You can see a 9-segment tube on the left side of this page. Bizarre. the 1 and the 3 and the 7 use the extra segments. The display is weird, indeed. Leading zeroes are NOT suppressed. Numbers display on the right as you enter them. (zeroes extend left).

© Sergei Frolov Interesting metallic grid covering the digits on Sergei's machine.

Manual Decimal Precision

An interesting observation:

There are no switches for precision. To get precision in the answer, you need to enter it in the equation.

i.e.: to get 1/9 to 4 decimals you have to enter

Neat, huh? The FIRST precision you enter is the one that counts... you can go

but you can't go...

It won't even LET you enter the decimal point (after the 4, above) in the 2nd number - entry is restricted to the precision currently in force (except for the first number). With this calculator you have to press C to bring up the display when its first switched on. You also have to do that if you don't like the precision of the previous answer. Diving by zero leaves the display blank, except for the righmost decimal point.Its all very alien.

Keyboard Variants

© Sergei Frolov

Two variants of the keyboard. Notice the different placement of the keys! Did the engineers building each machine have leeway over where each key was positioned? Or are we seeing the result of ergonomic improvements? Quite bizarre!

"The 4-71b is really neat, and also my favorite of the bunch! It is only four function, but the shape! I have never seen anything like it. They may have taken some US keyboard and put it in there own case, like the B3-25a. But I suspect this calculator is from around 71 or so, and they didn't do much copying then I don't think. "

- Kenton Green

The digit positions are labeled 1 to 8 (R to L), with the topmost (sign) position unlabeled.