Digital Research Computers -- LS-100 RAM Disk
DRC called this board the "Light Speed 100". It acted as a very fast CPM disk with a capacity of 256K. It utilized the Intel 8203-1 Dynamic RAM refresh controller and so was very reliable. It was also IEEE-696 compatible. All operations went through 4 constitutive I/O ports which was switch configurable. The board came with some basic software to get it going under CPM. Up to 8 boards could be configured in a S-100 system.
Board is untested and from a large collection of vintage hardware from a longtime IT manager