Introduced in 1984, and obsoleted by 1987, the Professional Graphics Controller (often called "Professional Graphics Adapter" and sometimes "Professional Graphics Array") offered slightly higher resolution and color depth than the EGA, up to 640 x 480 and 256 colors at 60 frames/second. It was intended for the computer-aided design market and included 320 kB of display RAM and an on-board microprocessor, which gave it the ability to do 3D rotation and clipping of images. While never widespread in consumer-class personal computers, its US$4,290 list price compared favorably to US$50,000 dedicated CAD workstations of the time.
The display adapter was composed of three physical circuit boards (one with the on-board microprocessor, firmware ROMs and video output connector, and the other two mostly providing RAM) and occupied two adjacent expansion slots on the XT or AT motherboard; the third card was located in between the two slots.
In addition to its native 640 x 480 mode, the PGC optionally supported the documented text and graphics modes of the Color Graphics Adapter.