Last Updated on: 5th November 2023, 04:27 pm
Web site: (not active)
Desktop environment: CLI
Architecture: Cray 1/X-MP
Based on: LTSS
The last version | Released: 1980’s
Cray Time Sharing System (CTSS) – an interactive operating system that has been installed on the Cray Research Inc., Cray-1 computers at Los Alamos. Currently, there are 4 Cray-ls, locally named by letters: Machines V, W, X, and Y. A fifth Cray-1 is expected to arrive in the fall of 1982 and will be named Machine Z.
The Cray-1 machines on which CTSS is running are located in the CCF. These machines are used primarily to run users’ programs and are called worker machines or simply workers. There are several other types of worker machines: Control Data Corporation 7600s and Cyber series machines.
The system that runs on the 7600s, called the Livermore Time Sharing System, is very similar to CTSS.
CTSS is an interactive timesharing operating system. You communicate with the CTSS machines by entering information at your terminal. This information is intercepted by several layers of computers, called Keyboard Communications Concentrators (KCCS) and Synchronous Communications Concentrators (SYNCS), to name a few, before it reaches the worker. Most of the communications between your terminal and these intermediate levels of computers are transparent to you. However, you may receive a message from a KCC when you attempt to sign on to a CTSS worker.
Perhaps the two primary features of the Cray-1, as compared to the other workers in the Network, are its large memory resources and its automatic vectorization capabilities.