Spy radio
Burst encoders
• • • Donate • • •
   Click for homepage
M-125-3MR3   Czech variant
Czech variant of the M-125-3 Fialka

The M-125-3MR3 (Russian М-125-3МР3) was the version of the M-125-3 Fialka that was used in Czechoslovakia during the Cold War. The machines were given on a lend/lease contract with the USSR (Russia) from the early 1960s onwards, until the collapse of the Soviet Union in 1992.

Destruction took place between the late 1990s and the early 2000s. Most of the machines were damaged by smashing them with a hammer and some were even burned. Like in Poland however, some machine miraculously survived demolition and in some cases collectors were able to rebuild complete Fialkas from the demolished remains.

The image on the right shows an M-125-3MR3, which is the Czech variant of the M-125-3. It is electrically identical to the Polish variant, but has a different keyboard layout, a different print head and differently wired cipher wheels (6K).
Czech Fialka M-125-3

The few machines that had survived demolition, first appeared on the European surplus market in 2005. Most of the Fialka machines that are in the hands of collectors today, are of this type. The quality of the surviving machines varies. Some are in excellent condition, whilst other are beyond repair. They cipher wheels do not have matching numbers as they had to be recovered seperately.

Standard PSU
Like most other countries of the Warsaw Pact, the Fialka machines that were used in Czecho­slovakia were not issued with the advanced Power Supply Unit (PSU) that the Poles had, but with a simpler 'standard' model. This standard PSU was also used in the former East-Germany (DDR).

The image on the right shows the standard PSU, of which two manufacturing variants exist. It is housed in a grey 'hammerite' metal case with rounded corners and consists of a transformer, a simple rectifier and some basic filtering.

It allowed the Fialka machine to be powered from a wide range of mains AC voltages as well as from the 24V DC network of a truck.

 More information
Standard Fialka PSU. Click for more information.

Czech Fialka M-125-3 Czech Fialka M-125-3 Close-up of the keyboard Keyboard of Czech M-125-3MN Front view of the M-125-3MN
1 / 5
Czech Fialka M-125-3
2 / 5
Czech Fialka M-125-3
3 / 5
Close-up of the keyboard
4 / 5
Keyboard of Czech M-125-3MN
5 / 5
Front view of the M-125-3MN

Czech keyboard
The drawing below shows the layout of the keyboard of the Czech variant of the Fialka. When used for communication in Russian, the Cryrillic characters at the bottom left of each key are used. The position of the Cyrillic characters is identical on all country-specific Fialka variants.

Layout of the Czech variant of the M-125-3 (Fialka) machine

At the bottom right is the Czech layout of the Latin alphabet. These letters are used in Latin-only Mode or in Mixed Mode (i.e. letter and numbers). The characters at the top left are used in Letter-Shift mode (i.e. after pressing A... in Mixed Mode) when typing Russian, whilst the characters at the top right are used in Czech Letter-Shift mode. When using the machine in Numerical Mode (i.e. the 30 ↔ 10 swtich set to '10') only the darker grey keys can be used. In this mode the characters at the top left of the keys are used, which implies the use of the Cyrillic print head.

Chech wheel wiring   6K
In 2005, the first Czech Fialka machines started appearing at the surplus market. Quite often these machines were in pretty bad condition, as they had officially been destroyed. Nevertheless, many collectors have meanwhile been able to get their hands on a working machine. When we got our first Czech Fialka machine up and running in 2005, we immediately traced the wheel wiring:

In this table, each row represents a wheel, whilst each column represents a single contact on a wheel. At the top of the table are the entry contacts which are at the right side of the wheel (i.e. the side with the spring-loaded contacts). The table itself shows the output contacts (i.e. the left side of the wheel). The positions of the Advance Blocking Pins are marked in red. At the far right is the total number of Advance Blocking Pins for each wheel.

 More wiring details

The Russian M-125-3M was supplied with the same accessories as the other M-125-3 variants, except for the spare print heads. As the M-125-3M was a Russian-only machine, the only print head that was used was the Mixed Mode Russian version which was present inside the machine. As a result, the axle that holds the test reflector inside the metal dust cover, has no room for additional print heads. Click any of the thumbnails below for additional information.

 Overview of the accessories

Original check list Metal dust cover that protects the machine and is used to store some accessories Metal box for collecting paper chad from the punched paper tape Paper feeder that holds a fresh paper tape reel Small hand crank for making corrections and for releasing a blocked mechanism Spare print heads Test reflector Spare set of wheels in aluminium can
Canvas wallet with various tools Oil can used for maintenance User manual Standard Power Supply Unit (PSU) Tempest complient Power Supply Unit (PSU) 24V service lamp used for seting up and maintenance Metal test triangle for the card reader Wheel opening tool
Wheel stepping   6K
When testing a Czech Fialka, either as a real machine or as a simulation, the following table might be useful when checking the wheel stepping mechanism. Put all wheels in their default setting (i.e. ring set to 'A', matching core with side '1' up with the mark set to 'A') and place them in the machine in the default order: АБВГДЕЖЗИК. Now lower the ruler and set the wheels to AAAAAAAAAA (just above the ruler). Next, type 30 random characters on the keyboard and compare the position of the wheels after each step with the following table:

Wheel А Б В Г Д Е Ж З И К
Position 1 2 3 4 5 6 7 8 9 10
0 А А А А А А А А А А
1 А Й А А А А Б А Б А
2 А Я А Й А А Б А В А
3 А Ю А Й А А В А Г А
4 А Ь А Я А Й Г А Д А
5 А Ы А Ю А Я Г Й Е Й
6 А Щ А Ю А Я Д Й Ж Й
7 А Ш А Ь А Ю Е Я З Я
8 А Ч А Ы А Ю Ж Я И Я
9 А Ц Б Щ Б Ю З Я К Я
10 А Х Б Ш В Ю И Я Л Я
11 А Ф Б Ш В Ю К Я М Я
12 А У Б Ч В Ю К Я Н Я
13 Б Т В Ч Г Ю Л Я О Я
14 Б С В Ц Г Ю М Я П Я
15 Б Р В Х Г Ь М Ю Р Ю
16 Б П В Ф Г Ь М Ю С Ю
17 Б О В У Г Ь Н Ю Т Ю
18 Б Н В Т Г Ь О Ю У Ю
19 Б М В С Д Ы П Ю Ф Ю
20 В Л Г С Е Ы Р Ю Х Ю

Front view of the M-125-3MN with top lid open
Older version
Before the M-125-3 was introduced in the late 1960s, its predecessor, the M-125 was used. It can easily be distinguished from the M-125-3 as its keyboard has rounded key tops whereas the key on the later machine are square. Furthermore it only has two letters on each key: a Cryllic one (in black) and a Latin one (in red). Furthermore these machines were issued with the standard (non-adjustable) cipher wheels. → More information about the older M-125.

The older M-125 and the later M-125-3 side by side (Polish versions shown here)

  1. Jörg Drobick, Nutzung der Fialka M-125
    Website: Der SAS- und Chiffrierdienst (SCD). Retrieved May 2014.

  2. Paul Reuvers and Marc Simons, The Fialka M-125 Reference Manual
    Copyright 2005-2009. Version 2.0, June 2009. ISBN 978-90-79991-01-3.
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: Sunday 06 July 2014. Last changed: Tuesday, 13 June 2017 - 20:53 CET.
Click for homepage