SAGE IV Computer
The SAGE II was the first computer designed and released by Sage Computer Technology. The design started in August 1981 and was first shown to the public at the 7th annual West Coast Computer Faire in March 1982 in San Francisco, California.
The SAGE IV came out in 1983, a year after the SAGE II. There never was a SAGE I or SAGE III system.
The SAGE IV used the same CPU logic board as the SAGE II, but added a second board that sat atop the first board.
This second PCB contained an additional 512 KB of DRAM, four serial ports for supporting more simultaneous users, and a controller to support a Winchester hard disk.
Price lists from 1983 have system configurations for a 6MB, 12MB, or 18MB Winchester hard drive. Eventually hard drives as large as 40MB were available.