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The '''Multi-Color Graphics Array''' or '''MCGA''' is a [[Video card|video subsystem]] built into the [[motherboard]] of the [[IBM PS/2 Model 30|IBM PS/2 Model&nbsp;30]], introduced on September 2, 1986, and [[IBM PS/2 Model 25|Model&nbsp;25]], introduced later on August 11. 1987; no standalone MCGA cards were ever made.<ref>{{Cite book |last1=Sanchez |first1=Julio |url=https://books.google.com/books?id=gZ5SDTpMR-MC&pg=PA122 |title=The PC Graphics Handbook |last2=Canton |first2=Maria P. |publisher=CRC Press |year=2003 |pages=122}}</ref>
The '''Multi-Color Graphics Array''' or '''MCGA''' is a [[Video card|video subsystem]] built into the [[motherboard]] of the [[IBM PS/2 Model 30|IBM PS/2 Model&nbsp;30]], introduced on September 2, 1986, and [[IBM PS/2 Model 25|Model&nbsp;25]], introduced later on August 11, 1987; no standalone MCGA cards were ever made.<ref>{{Cite book |last1=Sanchez |first1=Julio |url=https://books.google.com/books?id=gZ5SDTpMR-MC&pg=PA122 |title=The PC Graphics Handbook |last2=Canton |first2=Maria P. |publisher=CRC Press |year=2003 |pages=122}}</ref>


The MCGA supports all [[Color Graphics Adapter|CGA]] display modes plus 640&nbsp;×&nbsp;480 monochrome at a refresh rate of 60&nbsp;Hz, and 320&nbsp;×&nbsp;200 with 256&nbsp;colors (out of a [[List of monochrome and RGB color formats#18-bit RGB|18-bit RGB palette of 262,144]]) at 70&nbsp;Hz. The display adapter uses a [[D-subminiature|DE-15]] connector.
The MCGA supports all [[Color Graphics Adapter|CGA]] display modes plus 640&nbsp;×&nbsp;480 monochrome at a refresh rate of 60&nbsp;Hz, and 320&nbsp;×&nbsp;200 with 256&nbsp;colors (out of a [[List of monochrome and RGB color formats#18-bit RGB|18-bit RGB palette of 262,144]]) at 70&nbsp;Hz. The display adapter uses a [[D-subminiature|DE-15]] connector.
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MCGA is similar to [[Video Graphics Array|VGA]] in that it had a 256-color mode (the 256-color mode in VGA was sometimes referred to as MCGA) and uses 15-pin analog connectors. The PS/2 chipset's limited abilities prevents [[Enhanced Graphics Adapter|EGA]] compatibility and high-resolution multi-color VGA display modes.
MCGA is similar to [[Video Graphics Array|VGA]] in that it had a 256-color mode (the 256-color mode in VGA was sometimes referred to as MCGA) and uses 15-pin analog connectors. The PS/2 chipset's limited abilities prevents [[Enhanced Graphics Adapter|EGA]] compatibility and high-resolution multi-color VGA display modes.


The tenure of MCGA was brief; the PS/2 Model&nbsp;25 and Model&nbsp;30 were discontinued by 1992, and no manufacturer produced a clone of this display adapter except for [[Epson Equity]] Ie and Epson PSE-30, since the VGA standard introduced at the same time was considered superior.<ref>{{Cite book |last=REM |url=https://files.support.epson.com/pdf/e1e___/e1e___ps.pdf |title=Equity le - CGA/EGA/VGA/MCGA Video Mode Compatibility |publisher=Epson |year=1989 |pages=13}}</ref><ref>{{cite web |last=Farquhar |first=Dave |date=May 2022 |title=MCGA vs VGA |url=https://dfarq.homeip.net/mcga-vs-vga/ |url-status=live |website=The Silicon Underground}}</ref>
The tenure of MCGA was brief; the PS/2 Model&nbsp;25 and Model&nbsp;30 were discontinued by 1992, and no manufacturer produced a clone of this display adapter except for [[Epson Equity|Epson Equity Ie]] and [[Epson PSE-30]], since the VGA standard introduced at the same time was considered superior.<ref>{{Cite book |last=REM |url=https://files.support.epson.com/pdf/e1e___/e1e___ps.pdf |title=Equity le - CGA/EGA/VGA/MCGA Video Mode Compatibility |publisher=Epson |year=1989 |pages=13}}</ref><ref>{{cite web |last=Farquhar |first=Dave |date=May 2022 |title=MCGA vs VGA |url=https://dfarq.homeip.net/mcga-vs-vga/ |url-status=live |website=The Silicon Underground}}</ref>


==Software support==
==Software support==

Revision as of 08:10, 3 May 2023

Multi-Color Graphics Array
Release date1986; 38 years ago (1986)
Cards
Entry-levelIBM PS/2 Model 30 & 25 motherboards; Epson Equity Ie motherboard
History
PredecessorColor Graphics Adapter
SuccessorVideo Graphics Array

The Multi-Color Graphics Array or MCGA is a video subsystem built into the motherboard of the IBM PS/2 Model 30, introduced on September 2, 1986, and Model 25, introduced later on August 11, 1987; no standalone MCGA cards were ever made.[1]

The MCGA supports all CGA display modes plus 640 × 480 monochrome at a refresh rate of 60 Hz, and 320 × 200 with 256 colors (out of a 18-bit RGB palette of 262,144) at 70 Hz. The display adapter uses a DE-15 connector.

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 uses 15-pin analog connectors. The PS/2 chipset's limited abilities prevents 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 1992, and no manufacturer produced a clone of this display adapter except for Epson Equity Ie and Epson PSE-30, since the VGA standard introduced at the same time was considered superior.[2][3]

Software support

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 didn't attempt to use VGA-specific features such as multiple screen pages.

Games lacking support for 256-color graphics were forced to fall back to four-color CGA mode (or not run at all) due to the incompatibility with EGA video modes (320 × 200 in 16 colors, as well as sometimes 640 × 200 or 640 × 350). Some games, including point-and-click adventures from Sierra On-line and Lucasfilm Games, as well as simulation and strategy titles from Microprose solved this problem for low-resolution titles by supporting MCGA in its 320 × 200 256-color mode and picking the colors most resembling the EGA 16-color RGB palette, while leaving the other available colors in that mode unused.

Higher resolution titles were often unsupported unless graphics could be converted into either MCGA low or high (640 × 480 monochrome, which would also support 640 × 400 and 640 × 350 graphics with some letterboxing) in an acceptable fashion. An alternative approach used by a small number of (generally earlier) games was to use 4-colour CGA assets but make use of the adaptor's ability to freely change each of the palette colours for a slightly enhanced appearance.

Output capabilities

MCGA offered:

  • 640 × 480 monochrome (Mode 11h)
  • 320 × 200 in 256 colors (from a palette of 262,144) (Mode 13h)

CGA compatible modes:

  • 40 × 25 text mode with 8 × 8 pixel font (effective resolution of 320 × 200) (Mode 0/1h)
  • 80 × 25 text mode with 8 × 8 pixel font (effective resolution of 640 × 200) (Mode 2/3h)
  • 320 × 200 in 4 colors from a 16 color hardware palette. Pixel aspect ratio of 1:1.2. (Mode 4/5h)
  • 640 × 200 in 2 colors. Pixel aspect ratio of 1:2.4 (Mode 6h)

See also

References

  1. ^ Sanchez, Julio; Canton, Maria P. (2003). The PC Graphics Handbook. CRC Press. p. 122.
  2. ^ REM (1989). Equity le - CGA/EGA/VGA/MCGA Video Mode Compatibility (PDF). Epson. p. 13.
  3. ^ Farquhar, Dave (May 2022). "MCGA vs VGA". The Silicon Underground.{{cite web}}: CS1 maint: url-status (link)
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