Is there anything of which men say, See, this is new? It has been in the old time which was before us
Ecclesiastes 1:10

Tuesday, December 20, 2016

Serial Mainframe System “Strela”

The Mainframe “Strela” (Arrow). Magazine for youth “Znanie-Sila” № 7, 1956

Тhe first Soviet serial mainframe system was named “Strela” (Arrow). The computer was created in 1953, seven copies produced. It had 2-3 thousand operations per second speed, 43-bit memory into 2048 cells, operated floating point in the binary system. Two tapes represented external memory. The total amount of information on a single tape does not exceed 100 thousand 43-bit numbers. Memory originally performed on cathode-ray tubes: there were 43 tubes – one for each digit. Memory element represented an electrostatic charge of one of the 2048 points of screen. Writing and reading produced by an electron beam. Memory for tubes was later replaced by a more reliable memory on ferrite cores. Data entry carried from punched cards or using the tumbler registers located on the console; the results were outputted on the cards or wide format printer.


The principle of inter-node computer. Figure S.Kaplan. Magazine for youth “Znanie-Sila” (Knowledge is power) № 7, 1956


Structurally the construction was divided into standard cell containing from three to nine radio valves. The active elements performed on six thousand vacuum valves and two thousand semiconductor diodes. Warranty endurance of each radio valves was 500 hours and the trouble-free operation of the mainframe was twenty hours a day. Power consumption was 150 kVA. Heat carried out an air cooling system. The mainframe system occupied 300 square meters of the area.

All issued machines had hardware and software monitoring and diagnosis. The staff of one shift was 5-7 people.

Do not forget that the machine was set up in the war-ravaged country and it used entirely domestic (U.S. compatible) the high level electronic element base.

MORE: (in Russian) ЭВМ "СТРЕЛА"| ИЗ ИСТОРИИ ТЕХНОЛОГИЙ И НЕ ТОЛЬКО



The Great Seal Bug


Soviet young pioneers gave a carving of the Great Seal of the United States to U.S. Ambassador Averell Harriman. It hung in the ambassador’s Moscow residential office until 1952 when the State Department discovered that it was ‘bugged’. The Soviets were able to eavesdrop on the U.S. ambassador’s conversations for six years. A discovered bug was puzzle, since it had not batteries, no electric circuits and it was named The Great Seal Bug or The Thing.

Operating Principles

The Great Seal Bug was one of the first covert listening devices to use passive techniques to transmit an audio signal. It is considered a predecessor of current RFID technology.


The Thing was designed by Leon Theremin. It consisted of a tiny capacitive membrane connected to a small quarter-wavelength antenna; it had no power supply or active electronic components. The device, a passive cavity resonator, became active only when a radio signal of the correct frequency was sent to the device from an external transmitter. Sound waves caused the membrane to vibrate, which varied the capacitance “seen” by the antenna, which in turn modulated the radio waves that struck and were retransmitted by The Thing. A receiver demodulated the signal.
Theremin’s design made the listening device very difficult to detect, because it was very small, had no power supply or active components, and did not radiate any signal unless it was actively being irradiated remotely. These same design features, along with the overall simplicity of the device, made it very reliable and gave it a potentially unlimited operational life.

For his work, developer of the system, the prisoner Theremin, earned a personal freedom.

MORE: THE GREAT SEAL BUG STORY by Kevin D. Murray; Passive Resonant Cavity & "Spycatcher" Technical Surveillance Devices from archive.is