FINE ACQUISITION FOR COLLECTORS !!!

RARE and collectible item

The most popular Soviet programmable calculator Elektronika B3-34 (1983) 

The first programmable calculators B3-21, MK-46 and MK-64, although worked under the control of a program,  
had only two operational registers X and Y, and  working with the circular stack was very inconvenient. 
This was changed in 1980 by the programmable calculator B3-34, with fluorescent display and  priced at 85 roubles. 
It was another step forward!  It had a  stack based on four registers, 98 steps of program memory, 14 registers of memory instead of the seven available on the B3-21, 
and most importantly - the capability to organize cycles and work with index registers. It was a pleasure to work with this calculator.

Soon, in 1982, appeared its analogues, the B3-34 and MK-54, with fluorescent display and a more beautiful design, 
and costing on 20 roubles cheaper at the expense of using a  power supply of different type. The desktop variant  MK-56 was also developed.

One behind another,  the most popular scientific and technical magazines, such as "Science and Life", "Engineering - youth" and "Chemistry and Life" 
started to teach how to work with the calculator.  "Science and Life", started in October 1983 a special section named "Man with the calculator", 
talking about how to work with the B3-34, and including plenty of useful and game programs. 
The magazine "Engineering - Youth", beginning in 1985 included a column on programming the B3-34 under the name "The Calculator - your assistant" ,
and then organized the "Club of Electronic Games", which printed the most fascinating and fantastic stories: 
"The True Truth" and "Way to the Earth", here the readers were given the chance "to run into" the engineering of "landing" 
on a lunar surface and carry out a flight back from the Moon to the Earth by a ship, not adapted to such lunar flights, called the "Kon-Tiki".  
School kids and adult calculator users waited with impatience the next number of "Engineering - Youth" to continue their flight back to the Earth...

This calculator worked under the Reverse Polish Notation system, therefore, after entering the  first number, the key  is pressed, 
then the second number is entered and the corresponding operator key is pressed. 
For example, to multiply 2 by 3, it was necessary to press the keys: (result - 6).  
A stack consisting of four registers - X, Y, Z, T was used to store the operands. 
To enter a number after obtaining a result and to recall a number from one the memory  registers  (0.. 9, A.. D), the content of the X register, 
which is the display register, had to be moved to the Y register, causing Y to move to Z, and Z to T.   
Registers X and Y were used for most operations requiring operands.

In programming mode the code for each command takes one cell of memory. Branching commands  (transfers, loops, conditional transfers) take two cells. 
One cell for the operation code , and a second for the transfer address. 
In contrast with the  B3-21, the transfer address  can now be entered directly, instead of finding the correspondent operation code in a table. 
For example, to enter a transfer command to address 33 with the B3-21 it was necessary to enter [BP] [3] (the 3 key corresponded to code 34), 
in the B3-34 calculator it was only necessary to enter [BP] [3] [3].  
Although now one more keystroke is required,  it is no longer necessary to look for the operation code in a table.

However, the most interesting aspect of the B3-34 calculator and its analogues is the availability of undocumented features.  
These were useful  not only to write programs, but also to build special display messages. 
There are so many undocumented features  that they could deserve writing an additional article.

The  B3-34 calculator and its analogues, the MK-54 and the desktop MK-56, became so popular, that the developers from the "Crystal" Kiev factory decided to continue this line.  
In 1985 the new models MK-61 and MK-52 were introduced. They had one more memory register, 5 programs of 97 steps each, and ten additional functions. 
In addition, the MK-52 calculator had 512 bytes of permanent memory, which was not erased when the  power was disconnected.  
This memory was able to store both programs and data. 
The  MK-52 calculator also had special sockets for the connection of available program modules known as BRP (blocks of memory expansion). 
When designing the BRP blocks the developers again killed two rabbits at once by soldering in one block the matrix for two sets of  programs.
 By connecting a jumper, say, in rule 1,  one had the block BRP-3 with a mathematical set of the programs, 
then re-soldering the jumper to rule 2 - the block became the BRP-2 with  astro-navigational functions. 
Of course, this implied to lose the manufacturer warranty since to do that it was necessary to remove a sealed screw. 
This was divulged in one of the issues of  "Science and Life" magazine by a reader who in turn was told by one of the "Crystal" developers. I can imagine what would happen to this developer.
By the way, the MK-52 flew to the space in the "Soyuz TM-7", where it was supposed to compute the landing trajectory in case the onboard computer would fail.

Look an actual pictures above - You receive exactly what You see!!!
 
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