The UNIVAC 90/60 was a third-generation mainframe digital computer built by the UNIVAC Division of Sperry-Rand beginning in 1973. This system was a follow-up to the UNIVAC Series 70 machines which were derived from the RCA Spectra 70 mainframes; a family of systems that was acquired by UNIVAC when RCA abandoned the computer market in 1970.
Like its predecessors, the UNIVAC 90/60 had an instruction set that was nominally compatible with that of the IBM 360 and IBM 370 mainframe computers. Differences in the I/O architecture and memory management scheme prevented the UNIVAC from running IBM operating systems, so this was not a true "clone" like the Amdahl Mainframes or copies of the IBM Personal Computers.
I have a personal connection to this machine since it was the first "real" computer that I ever used and the first machine that I had the honor of programming. I was fortunate to become involved with computers at the very end of the mainframe era, when time-sharing was the most common way of interacting with these systems. Unlike the personal computers that came a few years later, these systems were seen as unbelievably powerful, extremely complex and utterly mysterious. There was also an intricate culture associated with them with its own system of ethics, folklore, and social hierarchy. This is something to explore in a sociological and anthropological context and something I hope to research and document in the future.
Although batch processing was still very much alive, most of my early interactions with the system used a Teletype Model 43 data terminal that dialed-in to the mainframe over the campus telephone network. I was using a statistical package called "MINITAB II" to complete my homework for a college-level course in statistics I was taking as part of "Project Enhance." This was an education program for academically "gifted" high-school students where they bussed you from your home school to the college to take high-level courses that the high schools didn't offer.