Magnetic core store replacement


This module was part of a radar system. Inserted into the video line driving a 512 line CRT monitor, it effectively provided controllable persistence on the operators radar screen. But how do you keep an essential system running when it depends on an electronic sub-system based around an obsolete magnetic core store? Sometimes it is cheaper to start again from scratch. We designed a form, fit, and function replacement based around an Actel A42MX series FPGA and a RAM chip. The Actel antifuse device was chosen because it operates at five volts, simplifying the design when the original equipment was built with 54 series TTL.