Professional Graphics Controller

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Professional Graphics Controller
PGC card
Release date1984; 37 years ago (1984)
ArchitectureIntel 8088
High-endIBM 5175 PGD
Matrox PG-640, PG-1280 and QG-640
Dell NEC MVA-1024
Everex EPGA
Orchid Technology TurboPGA
Vermont Microsystems IM-640 and IM-1024
PredecessorColor Graphics Adapter
SuccessorVGA / 8514

Professional Graphics Controller (PGC, often called Professional Graphics Adapter and sometimes Professional Graphics Array) is a graphics card manufactured by IBM for PCs.[1] It consists of three interconnected PCBs, and contains its own processor and memory. The PGC was, at the time of its release, the most advanced graphics card for the IBM XT and aimed for tasks such as CAD.[2]

Introduced in 1984,[3] the Professional Graphics Controller offered a maximum resolution of 640×480 with 256 colors at a refresh rate of 60 Hertz—a higher resolution and color depth than CGA and EGA supported. This mode is not BIOS-supported. It was intended for the computer-aided design market and included 320 kB of display RAM and an on-board Intel 8088 microprocessor. The 8088 ran software routines such as "Draw Polygon" and "Fill Area" from an on-board 64kB ROM so that the host CPU didn't need to load and run these routines itself.[3] 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 (even when the $4,995 price of a PC XT model 87[4]was included). It was discontinued in 1987 with the arrival of VGA and 8514.

Software support[edit]

The board was targeted at the CAD market, therefore limited software support is to be expected. The only software known to support the PGC are IBM's Graphical Kernel System, P-CAD 4.5, Canyon State Systems CompuShow[5][6] and AutoCAD 2.5.[7]

Output capabilities[edit]

PGC supports:


The display adapter was composed of three physical circuit boards (one with the on-board microprocessor, firmware ROMs and video output connector, one providing CGA emulation, and the third mostly carrying RAM) and occupied two adjacent expansion slots on the XT or AT motherboard;[8] the third card was located in between the two slots. The PGC could not be used in the original IBM PC without modification due to the different spacing of its 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, which could be enabled using an onboard jumper. However, it was only partly register-compatible with CGA.

Related monitor[edit]

The PGC's matching display was the IBM 5175, an analog RGB monitor that is unique to it and not compatible with any other video card without modification. With hardware modification, the 5175 can be used with VGA, Macintosh, and various other analog RGB video sources.[9] Some surplus 5175s in VGA-converted form were still sold by catalog retailers such as COMB as late as the early 1990s.[citation needed]

Hardware clones[edit]

See also[edit]


  1. ^ a b "IBM Personal Computer Professional Graphics Controller Technical Reference" (PDF). Retrieved 2016-08-08.
  2. ^ a b c "Professional Graphics Controller Notes". 2010-08-11. Retrieved 2014-06-19.
  4. ^ IBM PERSONAL COMPUTER AND IBM PERSONAL COMPUTER XT ENHANCED WITH ANNOUNCEMENT OF MATH CO-PROCESSOR OPTION // Announcement Letter Number 183-082 dated June 7, 1983 [Full PC line price list at bottom of document.]
  5. ^ "Professional Graphics Controller Notes". 2010-08-11. Retrieved 2018-08-22.
  6. ^ "CompuShow History". Retrieved 2016-08-08.
  7. ^ InfoWorld 29 Sep 1986, p. 49, at Google Books
  8. ^ "The IBM PGA Graphics Adapter". Archived from the original on 2016-08-07. Retrieved 2016-08-08.
  9. ^ "Google Discussiegroepen". Retrieved 2014-06-19.
  10. ^ "InfoWorld". Google Books. Retrieved 2014-06-19.

External links[edit]