Even I can tell the difference!
Even I can tell the difference!
IBM Selectric Bug
Operation GUNMAN - how the Soviets bugged IBM typewriters
The Selectric Bug was a sophisticated digital eavesdropping device, developed in the mid-1970s by the Soviet Union (USSR). It was built inside IBM Selectric II and III typewriters [4] and was virtually invisible and undetectable. A total of 16 devices were found inside typewriters that were in use during at least 8 years at the US Embassy in Moscow and the US Consulate in Leningrad
The advanced digital bugging device was built inside a hollowed-out metal supporting bar that runs from left to right inside the IBM typewriter. It registered the movements of the print head (ball), by measuring small magnetic disturbances caused by the arms that control the rotation and elevation of the print ball. A typical IBM Selectric II typewriter is shown in the image on the right.
At least five different versions, or generations, of the bug were discovered by the Americans, some of which were powered by a DC battery voltage. Others were powered by the AC mains or both
Furthermore, the devices were remote controlled by the Soviets from outside the building. When the typewriter was turned ON, and the device was activated remotely, it sent its data via radio in short bursts 2 to a nearby listening post. Although there was some ambiguity in the intercepted data, the Soviets were then able to recover the typed plaintext by using the laws of probability.< p> The Selectric:
The electronics:
The bug was fairly large and consisted of state-of-the-art integrated circuits and single-bit core memory. It was completely hidden inside a hollow support bracket at the bottom of the keyboard mechanism, and was invisible to the naked eye, but also to the detection equipment of the era. Only an X-ray scan could reveal the presence of the device, which is shown in the image below. It contains special components to hide its presence even from non-linear junction detectors (NLJD).