Imagery intelligence satellite ferrite core memory cube

Hybrid microcircuit named 4SJA-20 (4СЯ-20) is a KP128/22 (КП128/22) ferrite core memory cube with additional electronic boards installed on the sides. Four boards with 64 chipless decoders (16 on each side) are installed on the four sides of the cube. At the top there is a metal cover with mounting holes in the corners and plugs on each sides. The sides are marked by the russian letters А, Б, В, Г. The name of the hybrid microcircuit, production code and serial number printed on the top cover. At the bottom of cube are printed circuit board with contact pads. Through these contacts, the several cubes were connected by wires. Excluding the end caps, the dimensions of the cube are 16x20x22 mm. The cube was used in spacecrafts, in particular, the "Yantar-4KS1" (Янтарь-4КС1) military surveillance satellites (also known as 11F694).

Internal structure and specifications

The memory capacity is 128 of 22-bit words or 252 bytes, but only 20 bits of each word are used for data, the remaining for ECC.

Additional information

Produced at the Leningrad Ferrite Plant (now OJSC Magneton Plant)

Images (click to enlarge)