Multi-Color Graphics Array

Lore & Background

The MCGA was built into the motherboard of the IBM PS/2 Model 30 (April 1987) and Model 25 (August 1987); no standalone MCGA cards were ever made. It supported all CGA display modes plus 640×480 monochrome at 60 Hz and 320×200 with 256 colors (from an 18-bit RGB palette of 262,144) at 70 Hz. The display adapter used a DE-15 connector, sometimes called HD-15.

MCGA is similar to VGA in that it had a 256-color mode (the 256-color mode in VGA was sometimes referred to as MCGA) and used 15-pin analog connectors. However, the PS/2 chipset's limited abilities prevented EGA compatibility and high-resolution multi-color VGA display modes. The tenure of MCGA was brief; the PS/2 Model 25 and Model 30 were discontinued by 1990, and the only manufacturer to produce a clone was Epson, in the Equity Ie and PSE-30, since the VGA standard introduced at the same time was considered superior.

Software support for the 256-color mode proved most popular for gaming. 256-color VGA games ran fine on MCGA as long as they stuck to the basic 320×200 256-color mode and did not attempt VGA-specific features such as multiple screen pages. Games lacking 256-color support were forced to fall back to four-color or two-color CGA modes, or never run at all, due to incompatibility with EGA video modes. Some games solved this by supporting the MCGA's 320×200 256-color mode and picking colors resembling the EGA 16-color RGB palette.

Reader's Guide

The MCGA's significance lies in its role as a transitional display standard bridging CGA and VGA. It introduced a 256-color mode (320×200) from a palette of 262,144 colors, which later became a hallmark of early VGA gaming. However, its lack of EGA compatibility and high-resolution multi-color VGA modes limited its software support. Games that relied on EGA-specific modes (320×200, 640×200, or 640×350 in 16 colors) often failed on MCGA, forcing developers to either fall back to CGA modes or adapt to MCGA's 256-color or monochrome modes. The adapter's brief tenure—the PS/2 Model 25 and Model 30 were discontinued by 1990—and the simultaneous introduction of the superior VGA standard meant few clones were produced (only by Epson). Despite this, the 256-color mode proved popular for gaming, and some titles from Sierra On-line, Lucasfilm Games, and Microprose supported it by using colors resembling the EGA palette. The MCGA's legacy is as a short-lived but influential step toward the analog, high-color VGA standard.

Did You Know?

• The MCGA's 256-color mode was sometimes referred to as MCGA even when implemented on VGA.
• The only clone manufacturer of MCGA was Epson, in the Equity Ie and PSE-30.
• Games lacking 256-color support on MCGA were forced to fall back to four-color or two-color CGA modes due to EGA incompatibility.