TOPS-10

TOPS-10 supported shared memory and allowed the development of one of the first true multiplayer computer games.

This application was perhaps the first so-called CB Simulator that allowed users to converse with one another in what is now known as a chat room.

TOPS-10 had a very robust application programming interface (API) that used a mechanism called a UUO or Unimplemented User Operation.

[4] The easiest way for the hobbyist to run TOPS-10 is to acquire a suitable emulator[5][6] and an operating system image.

[8] [9] Paul Allen maintained several publicly accessible historic computer systems, including a DECsystem-2065 running TOPS-10.