Standard Television Interface Circuit

The AY-3-8900, also known as the Standard Television Interface Chip or STIC, is a video display controller (VDC) produced by General Instrument for use with their CP1600 CPU in games consoles. It is best known as the basis for the Mattel Intellivision.

The STIC is typical of VDCs of the era, using a grid of character-like cells to draw a background graphic and then using up to eight sprites they called "movable objects" (MOBs), to produce animation. The overall resolution is 167 × 105 pixels in NTSC (in the 8900-1 model) and 168 × 104 pixels in PAL (8900 model), but only visible in an area of 159 × 96 pixels. The extra pixels around the visible area allow sprites to be placed in those locations and then smoothly move on-screen. The background consists of a 20 × 12 grid of 8×8 patterns known as "cards", which can be used as characters or other shapes. The STIC also computes collision information between the objects and screen borders.