5E26 computer ferrite core memory

5E26 (5Э26) computer 5E26 is specialized control small-sized mobile high-performance digital computing complex for use in missile air defense systems of the S-300 family. Produced since 1978. The RAM board is part of the "F" unit. Depending on the configuration of the computer, the number of "F" units can be three or five. The unit consists of several elements, the main of which is a metal plate rotating on hinges, on both sides of which there are printed circuit boards with ferrite matrices and other elements. Along the edges of the plate there are six connector plugs through which the plate is connected to other parts of the "F" unit. The whole block weighs 41 kg, the plate itself is 12.6 kg.

Internal structure and specifications

The RAM capacity is 4096 binary numbers. The bit width of each number is 36 bits (32 information and 4 control). In other words, the total memory capacity is 18 kilobytes of which 16 kilobytes is used for data, and the remainder is used for ECC. Ferrite cores are toroidal M101P-6 type. The outer diameter is 0.6 mm, the inner diameter is 0.4 mm, the height is 0.13 mm, and their total number is 147456 pieces (256 rows and 576 columns). Structurally, the ferrite cores are divided into six separate groups, sealed with a protective compound and covered with plastic covers.

Memory organizing type is 2.5D. This means that three wires pass through each magnetic core - address, address-bit and reading. Each row of the ferrite rings matrix can store 16 words each 36 bits (total 576 rings). Stitched with 288 address lines, of which 256 are working and 32 are reserved. In addition to the ferrite matrices, the board contains the address and address-bit parts, which ensure the selection of the required buses and the formation of the required current values in them.

Additional information

Made dy Zagorsk Electromechanical Plant in 1988.

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