working USSR Magnetic Ferrite Core Memory Plate BP-20 RAM 4096 bit 1978 Manual

Ferrite Core Memory Plate manufactured in the USSR in 1978 

Electronic copies of Technical documentation in Russian may be provided if required.

The board outside dimensions: 11.5 x 11.5 cm (~ 4.8 x 4.8 inch in US unit of length)

The frame outside dimensions (without pins): 10 x 10 cm (~ 3.9 x 3.9 inch in US unit of length)

Toroid dimensions: 1.0 x 0.7 x 0.35 mm (as it is written in operation manual)

Capacity: 1 tiny ferrite toroid = 1 bit

A 64 x 64 core memory plate stores 4096 bit of data

The plate is one of 18 plates forming a ferrite core memory BP-20 block. The capacity of the whole block is 73728 bit (9 Kb)

Condition: excellent working and cosmetic condition

The BP-20 memory block  is designed for information recording, storing and issuing in random access memory devices (shown on Pic.11-12)

TECHNICAL DATA

 ARRANGEMENT AND WORK OF COMPONENTS OF THE UNIT

FERRITE MATRIX

1      Cores with a rectangular hysteresis loop ЗВТ-1К 1.0 х 0.7 х 0.35 mm are used as a memory element in a ferrite matrix. The cores are structurally integrated in one frame of the 1M-2 type by a common system of wires and form a matrix with a capacity of 4096 one-bit words. 64 coordinate wires pass in the matrix along the "X" and 64 ones along the "Y", forming an address grid of 64 x 64.

2  The output winding for improving the signal-to-interference ratio is composed of two unconnected parts, each of which covers 2048 cores.

3       The ban winding is also divided into two parts and connected to two independent from each other ban current generators. This helps to improve the ban pulse parameters and facilitates the thermal operation of the unit.

4     The ban and read winding are sewn in such a way that simultaneously two windings cover only 1024 ferrite cores. This reduces twice interference from half-selected cores and parasitic pickups in half-cycles of reading and writing.

The ferrite core memory block was a part of punched computer center М5000Д. It was produced at the Industrial and Technical Association “Sigma”, Vilnyus.

As it is written in technical specification “Punched computer center intends for the solution of the mass economic tasks connected with the account, management and planning of a production activity of the enterprises and the organizations, and also for the solution of other tasks demanding mathematical and logic processing of large volumes of alphanumeric information of data”. 

Core memory is non-volatile storage – it can retain its contents indefinitely without power. It is also relatively unaffected by EMP and radiation. These were important advantages for some applications like first generation industrial programmable controllers, military installations and vehicles like fighter aircraft, as well as spacecraft, and led to core being used for a number of years after availability of semiconductor MOS memory.

To know more about Magnetic-core memory one can turn to Wikipedia and to other sources