Elektronika B3-21

Prototype 5.89MB PDF Final 3.24MB PDF Passport 822KB PDF

© Sergei Frolov © Sergei Frolov

LED LED display close-up.

Fluorescent Fluorescent display close-up.

© Sergei Frolov LED backplate. That's an astronomical price! Each serial number was hand-engraved. © Sergei Frolov The fluorescent version's backplate. Note the interesting overstamp of the price!

Note about function "e^ix" in B3-21, MK-46, MK-64. After this function is called, the calculator places sin x into reg. Y and cos y into reg. X.. Through this function one may easy calculate "tan" function by pressing "div" key.

Note about right-rotate stack in B3-21. It is not present on the machines MK-46, MK-64, MC-1103 (key under /-/). Function [P] [/-/] on MK-46 and others return error message. I think that this change was made after correction of the stack error: B3-21 after calculating some complex formula, such as Sin 2, will break the stack. In MC-1103 (may be others, too) this bug has been corrected. Maybe by removal of right-rotate stack function and correction of the hardware.

Prototype!

Prototype sitting in clamshell box, with manuals

Backplate sticker

As the picture shows, this machine comes in a clamshell plastic storage box, but it's really quite unsuited to the machine. However, the box is moulded with Elektronika and has a factory-origin "b3-21" insert, so it seems original. Igor tells me that the manual has "pilot" (prototype) written on it, and this together with the unusual marking on the back (exact date of manufacture and very low serial number) convinces me that this was an early pre-production prototype of this machine.

This prototype machine uses the LED display variant. There are several cosmetic differences between the prototype and production versions. The blue body is a navy colour in the prototype; the factory is different, and the backplate is a sticker as opposed to a moulded-in version. Differences in the manual are as-yet unknown.