Click for homepage
USSR
Rotor
Fialka
  
Fialka Test Device
Unknown diagnostics device

For repair and maintenance of a Fialka cipher machine, it is likely that a special test device was available to service technicians. This device was connected to the special test socket at the left side of the later M-125-3 machines. For this, the existing shorting connector had to be removed temporarily. This socket is not available on the earlier M-125 machines. So far we have never seen any kind of Fialka test device, so we can only speculate about its functionality.

The test socket has 35 contact pins, divided over three rows, much like a D-type connector. It is wired to various parts of the Fialka, including the power supply, the keyboard encoder and the printer. In normal use, a plastic shorting plug should be present in the test socket (see below).

We recently found the connector that fits the test socket. It is shown in the image on the right. The connector was probably used for the connection of a test device. The shorting plug must be removed before the test connector can be fitted. More images of this connector are below.
  

Inside the shorting plug (that is normally present in the socket) are 8 shorting wires. It is fixed to the socket by means of two screw terminals. Without this plug, Fialka will not work. When removing the plug from a working Fialka, be careful not to lose it. The image below shows how the shorting plug is wired and how it should normally be fitted to the test socket. It shows connector Ш2 when looking into the socket from the left side of the machine.


When the shorting plug is removed, the 24V power supply is cut-off. Furthermore, the data path from the mechanical 5-bit keyboard encoder to the diode matrix is interrupted, so that the output of the keyboard can be checked and test characters can be sent to the input of the printer.

Test connector
Test connector
Test connector
A
×
A
1 / 3
Test connector
A
2 / 3
Test connector
A
3 / 3
Test connector

Documentation
  1. Fialka Reference Manual
    Crypto Museum, Paul Reuvers & Marc Simons.
Further information
Any links shown in red are currently unavailable. If you like the information on this website, why not make a donation?
© Crypto Museum. Created: Monday 07 July 2014. Last changed: Thursday, 07 January 2021 - 12:20 CET.
Click for homepage