Professional Graphics Controller

The Professional Graphics Controller ( PGC) was a graphics card manufactured by IBM for the PC XT and PC AT. Compared to other contemporary graphic solutions of the PGC was very progressive. He offered hardware acceleration for 2D and 3D graphics for professional CAD applications and consisted of three interconnected printed circuit boards, which hosted its own processor and memory.


The monitor IBM 5175 is the right to PGC card Monitor. It is an analog RGB monitor, which is specially designed for this card. Normally he can be with any other graphics card run, but it can be converted and can then, old Macintosh computers and other analog RGB video sources operated with VGA cards. On VGA converted Remainder of 5175 were sold off in the American shipping trade partly in the early 1990s.


The PGC was introduced in 1984 and offers a higher resolution and color depth than the EGA standard from the same year. With the support of a resolution of 640 × 480 pixels with 256 colors ( from a palette of 4096 colors) and 60 Hz refresh rate is the PGC even the first VGA cards, which were introduced in 1987, superior. Games with this graphics quality were implemented until the early to mid 1990s for SVGA cards. The mode is not supported by the BIOS interface.

The PGC aimed at the market for professional CAD workstations and has - for the time gigantic - 320 KB of video memory and its own Intel 8088 processor, which applications could be supported in tasks such as the rotation of images in 2D by the hardware. In computers, for ordinary users of the PGC never found a large spread, but put an IBM PC XT / AT with a PGC, which had a list price of 4,290 U.S. dollars, for professional users a very attractive alternative to CAD workstations is that often cost about 50,000 dollars.

With the advent of VGA cards of the PGC was finally set.


The PGC consists of three boards. One contains the main graphics processor, firmware ROM chips and the video output; one is responsible for the emulation of CGA, and the third contains mainly the graphics memory. On a motherboard, two ISA slots are occupied by the PGC; the third board is made ​​between the others, which take the space above the slots in claim both. For space reasons, the PGC could be used only from the PC XT.

In addition to the standard mode of 640 × 480 pixels, supports the PGC on request the official text and graphics modes of the CGA. This can be set with a jumper on the board. However, the PGC is register-level only partially compatible with the CGA, so the CGA emulation can be disabled and the PGC be operated without conflict then combined with a genuine CGA or EGA card.