Tymshare, Inc was a time-sharing service and third-party hardware maintenance company. Competing with companies such as CompuServe, Service Bureau Corporation and National CSS. Tymshare developed and acquired various technologies, such as data networking, electronic data interchange (EDI), credit card and payment processing, and database technology. It was headquartered in Cupertino in California, from 1964 to 1984.
In 1984, Tymshare was acquired by McDonnell Douglas, to which Tymshare had sold its hospital accounting service in 1982. by Thomas O’Rourke and David Schmidt, two former employees of General Electric's Computer Department. The company was entering the new market of time-sharing, which at that time was expected to grow rapidly. GE would itself soon enter this market as well, after collaborating with Dartmouth College.
Tymshare initially focussed on the SDS 940 platform, initially running at University of California Berkeley. They received their own leased 940 in mid-1966, running the Berkeley Timesharing System, which had limited time-sharing capability. IBM Stretch programmer Ann Hardy rewrote the time-sharing system to service 32 simultaneous users. By 1969 the company had three locations, 100 staff, and five SDS 940s.
In 1968, LaRoy Tymes and Norm Hardy developed the idea of creating a network with minicomputers to communicate with the mainframes. The minicomputers started off as an inexpensive 12-bit computer from General Automation and soon became a more capable 16-bit Varian 620i—would serve as the network's nodes, running a program called a "supervisor" which routed data, performed diagnostics, and kept network statistics; a local program at each node, dubbed a "leprechaun," handled log-in, security, and diagnostics. The supervisor was written in assembly code by Tymes for the SDS 940, with architectural design contributions from Hardy in late 1969. The network became fully operational in 1970, and by 1972 the resulting Tymnet system connected 40 cities in the United States. Tymnet was a centralized network, unlike ARPANET; it featured centralized password storage, statistical multiplexing, flow management, and great attention to security issues. Taylorix-Tymshare offered applications, e.g., the eMail system "OnTyme" based on Tymnet, the multi-dimensional database system "Express" [now owned by Oracle, but no longer promoted ]. Marketing departments of some large companies (like Johnson&Johnson or BAT) used Express (available via type-writer in time-sharing mode, later on also available on PC) for the analysis of Nielsen or GfK sales data. Taylorix-Tymshare ceased operation in 1986.
In 1974, a second version of the Supervisor software became operational. The new Tymnet "Engine" software was used on both the Supervisor machines and on the nodes.
After the migration to Interdata, they started developing Tymnet on the PDP-10. Tymshare sold a copy of the Tymnet network software to TRW, which created its own private network, TRWNET.
In the 1970s, Tymshare, which had used Digital Equipment's operating system TOPS-10 for its PDP-10s, began independent work on the OS for their systems, called it TYMCOM-X, and implemented a file system that supported random access, paging with working sets, and spawnable processes. The OS work was done by a group of eleven people: Bill Weiher, Vance Socci, Allen Ginzburg, Karen Kolling, Art Atkinson, Gary Morgenthaler (founder of the company that produced INGRES), Todd Corenson, Murray Bowles, Randy Gobbel, Bill Soley, and Darren Price. Most Tymnet development was then done on TYMCOM-X. Also in the 1970s, Tymshare acquired the Augmentation Research Center from SRI International.
Tymes and Rinde then developed Tymnet II. Tymnet II ran in parallel with the original network, which continued to run on the Varian machines until it was phased out over a period of several years. Tymnet II's different method of constructing virtual circuits allowed for much better scalability.
Tymnet, Inc. spun off
In 1976, Tymnet Inc. was spun off from Tymshare Inc. and became an FCC "common carrier" which allowed it greater latitude as a communications service but placed its rate-setting under regulatory review. In this model, Tymnet allowed users to connect their host computers and terminals to the network, and use the computers from remote sites or sell time on their computers to other users of the network, with Tymnet charging them for the use of the network. of which the Tymshare System XXVI was the main focus.
The Foonly F4 was remarketed as the System 26KL (another name for the Tymshare System XXVI).