The Imlac PDS-1 is a graphical minicomputer made by Imlac Corporation (founded in 1968) of Needham, Massachusetts. The PDS-1 debuted in 1970 and is considered to be the predecessor of all later graphical minicomputers and modern computer workstations. The PDS-1 had a built-in display list processor and 4096 16-bit words of core RAM. The PDS-1 used a vector display processor for displaying vector graphics as opposed to the raster graphics of modern computer displays. The PDS-1 was often used with another flagship Imlac product, a typesetting program called CES.
The PDS-1 was used in many pioneering computer applications. The FRESS hypertext system had enhanced capability and usability if accessed from a PDS-1 system; the user could make hyperlinks with a light pen and create them simply with a couple of keystrokes. Multi-window editing on FRESS was also possible when using the PDS-1.
The PDS-1 also had the capability to run remote graphical programs such as those that ran on the Stanford AI Lab's main computer. The PDS-1 was also able to run Mazewar, the first online multiplayer computer game. The PDS-1 connected to a host PDP-10 computer (located at MIT) running ITS over Arpanet and the Mazewar program. Up to 8 players running PDS-1 minicomputers or other terminals could access MIT's Mazewar host. The PDS-1 was also important during the early days of Arpanet when network graphics protocols were under consideration.