I think there were larger platters. On Thu, 20 Feb 2003, Murray McCullough wrote: may have produced and maybe these platters In about 1976 University of Missouri Bioengineering Program acquired an "IBM surplus image system" from somebody "unknown" out west. They sent a couple of graduate students to pick up the system in a U-Haul truck which was very overloaded. When we rolled the PSU down the hall on castors it left grooves in the floor tile because of the weight. There were 3 cabinet units each 6 feet high and 5 feet wide. One was the power supply, one was the disk controller and the other was the disk. It had a "very large" disk platter that ran vertically, if I remember correctly they were about 3-4 feet in diameter. Interesting noise when they spun up, kind of like turbine engine. There were two clamshell halves that were opened to access the platter, each track had a fixed head over it. Stored on each track was the image on a single display station. By switching between tracks you could access different images. There was a vacuum pump to remove the air if you opened the clamshells to adjust the heads. Each of the display stations had an integrated keyboard and a proximity or optical pen to select menu items. We wanted to investigate distributing medical images rapidly throughout a hospital. It was a one of the kind and after a few head crashes that was the end. We then bought a Ramtek display of 256 X 256 by 8 bits instead for $50K. It sat in a real compuer room with: an Interdata 8/32 a PDP 11/50 running MUMPS with 2 RK05's a PDP 11/20 running DOS-11 with 3 RK05's and a TU10. The SEL, PDP 8 with ASR-33, IBM 026 and IBM 029 were next door. Back in the punch card days of old. Mike