Compatible Time Sharing System (CTSS)
Definition - What does Compatible Time Sharing System (CTSS) mean?
The Compatible Time Sharing System (CTSS) was developed at the MIT Computation Center in the 1960s and 1970s. The design of the CTSS represents the beginning of the idea that operating systems can work on multiple threads or “multitask.”
Techopedia explains Compatible Time Sharing System (CTSS)
The original Compatible Time Sharing System was backward-compatible with the Fortran Monitor System. It worked on an IBM 7094 mainframe computer with two 32K banks of core memory. The second bank was used for timesharing implementation. CTSS was connected to printers, punch card readers and tape drives.
Time sharing means the system can allocate resources for two tasks or processes at once. This was a major advance, since earlier mainframes and computer systems only worked on one process at a time, in a linear fashion. Time sharing and multi-process and multi-thread systems paved the way for the highly advanced operating systems of the last three decades.
Eventually, designs like CTSS gave way to more modern MS-DOS systems in the 1980s and on to modern Windows and OSx systems in use today.