Abstract: A system for producing video signals representative of video patterns having operator-selected video attributes is disclosed. A vertical bit memory includes a plurality of vertical entity memories, each vertical entity memory having a memory bit for each line of a video frame. A horizontal bit memory includes a plurality of horizontal entity memories, each horizontal entity memory having a memory bit for each elemental horizontal reference position of a video frame. A vertical address generator is used to access the vertical entity memories in parallel. A horizontal address generator is used to access the horizontal entity memories in parallel. Means are provided for entering in the horizontal entity memories and vertical entity memories, respectively, binary indications of operator-selected horizontal and vertical coordinates defining diagonally opposite corners of operator-selected video patterns for one or more operator-selected entities.