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.