SKU: 86.1

• BIAX ROM Memory PCB manufactured in the USSR in 1991

Dimensions: 26 x 17 x 2 cm (approx. 10.24 x 6.69 x 0.79 inches)
Weight: 295 g (approximately 0.65 pounds)
Condition: used vintage condition. The 2ДС628А Diode assemblies are missing. Please, see pictures attached. The PCB was a part of Memory cassette.The memory cassette was a part of the ДЗУ-Э-8К-М long-term storage device block, which was in turn a part of the SV-4-01 Special computer (СВ-4-01) implemented on ferrites.
The SV-4-01-EVM Specialized computer was developed in the 80-s for air defense troops.
It operated inter avia in radar company’s 86Ж6 \"ПОЛЕ-МЭ\" automated control unit. Automated control unit was intended to collect and process radar information, to manage standard radar equipment, and to issue data to air defense command posts. Long-term memory device with data electrical overwriting was intended for storing programs, subroutines and various constants.
The memory drive of the long-term storage device block was used to record and store 8192 36-bit words with a sampling time of 1.2 μs and a minimum cycle of 1.5 μs. It consisted of eight memory cassettes. Each cassette included a diode decoder, BIAX ferrite memories with a bus system for recording, polling and reading.
BIAX (biaxial ferrite core), is a ferrite core with a branched magnetic circuit and two apertures that do not intersect and which have perpendicular axes. It is used as a memory or logic element in technical automation facilities and in digital computer technology. BIAX was used in long-term memory devices, magnetic cores memory devices with a rapid change of the information, where the slow recording is permitted. Frequency of recording is 200 - 300 kHz, and 2 - 5 MHz for reading.
The memory BIAX provides for operative recording, storage, and nondestructive readout.
This characteristic is due to the fact that the directions of the magnetic fluxes in the common region of the two closed interconnected magnetic circuits of the BIAX are mutually perpendicular and, upon simultaneous magnetic field reversal (recording of information), the resultant magnetic flux in the plug wire takes up the most favorable orientation.Here the magnetic fluxes around each aperture vary up to 0.7 of their maximum value.
An interrogation pulse causes a practically instantaneous change of orientation of the domains of the plug wire in the direction of the flux in the interrogation magnetic circuit.
This leads to a reduction of the flux in the recording magnetic circuit and the emergence of an electromotive force (readout) in the output winding.
After the shutoff of the interrogation pulse in the plug wire, the original distribution of the fluxes is restored without additional input.Unlike ferrite rings BIAX enables to re-read the recorded information without its destruction. Thus no time is required to restore it.The logic BIAX differs structurally from the memory type by the absence of a plug wire.
During its operation, the magnetic fluxes and their signs vary in the regions of the magnetic circuit common to both apertures.There are several varieties of BIAX that differ in construction (symmetrical and nonsymmetric), in properties of magnetic circuit material, and so on.
The primary virtues of the BIAX are its small dimensions, very rapid response (particularly in readout at small energy inputs), high reliability, and comparatively low cost for automated production and sorting.