early raster display systems

Bob said: Data Disc made a large graphics system meant to connect to mainframes around 1972. -- Data Disc goes back well into the 60's with video disk display systems. Hazeltine is even earlier. Disks and drums were used as frame stores along with recirculating magnetorestrictive delay lines in the days before semiconductor shift register memories. RAM replaced the shift registers in the 70's. But this all is getting well off the subject of raster display terminals. There were lots and lots of people making expensive frame stores (Ramtek, Genesco, etc.) Not so many were making things small/cheap enough to be used as terminals. Ramtek and others (trying to remember when Chromerics started) eventually got into that business. PCs and Workstations wiped out the graphics terminal market by the early 80's. Was interesting to find out ISC goes back to 1973.