Multi-Color Graphics Array

{{short description|Video subsystem built into the motherboard of the IBM PS/2 Model 30}} {{Multiple issues|{{More citations needed|date=May 2023}} {{More footnotes needed|date=May 2023}}}} {{Infobox GPU | name = Multi-Color Graphics Array | image = | codename = | created = {{Start date and age|1987|04|2}} | transistors = | entry = IBM PS/2 Model 30 & 25 motherboards; Epson Equity Ie motherboard; Delta Computer DG-630 motherboard<ref name=deltagoldii>{{cite journal | last=Brownstein | first=Mark | date=May 30, 1988 | url=https://books.google.com/books?id=4D4EAAAAMBAJ&pg=PA27 | title=Delta Announces PC-Compatible Product Line | journal=InfoWorld | publisher=IDG Publications | volume=10 | issue=22 | page=27 | via=Google Books}}</ref> | midrange = | highend = | enthusiast = | openglversion = | d3dversion = | predecessor = Color Graphics Adapter | successor = Video Graphics Array }} thumb|Simulated image as displayed using MCGA 640x480 resolution and color abilities. thumb|Simulated image as displayed using MCGA 320x200x256 resolution and color abilities. thumb|Simulated image as displayed using MCGA 320x200x4 graphics resolution and color abilities. thumb|Simulated image as displayed using MCGA 640x200 resolution and color abilities The '''Multi-Color Graphics Array''' or '''MCGA''' is a video subsystem built into the motherboard of the IBM PS/2 Model 30, introduced in April 1987,<ref name=":0">{{Cite news |last=Petzold |first=Charles |date=July 1987 |title=Triple Standard - Three New Video Modes from IBM |url=https://books.google.com/books?id=LRBokcwLB70C&dq=Multi-Color+Graphics+Array+MCGA&pg=PA132 |work=PC Magazine |pages=131, 132, 133}}</ref> and Model 25, introduced later in August 1987;<ref name=":1">{{Cite book |url=https://books.google.com/books?id=WSBVAAAAMAAJ&dq=Multi-Color+Graphics+Array+MCGA&pg=RA14-PA13 |title=U-M Computing News |date=1988 |publisher=Computing Center |pages=13 |language=en}}</ref> 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|isbn=9780203010532 }}</ref><ref>{{cite web | url=https://www.vogons.org/viewtopic.php?t=95426 | title=MCGA Games (PC/DOS) - LCD vs CRT \ VOGONS }}</ref><ref>{{cite web |date=20 December 2014 |title=Epson Equity 1e |url=https://ancientelectronics.wordpress.com/2014/12/19/epson-equity-1e |website=ancientelectronics - retro computing and gaming plus a little more}}</ref><ref>{{cite web |last=Hierophant |first=Great |date=28 April 2012 |title=Unique PC Hardware & Game Support |url=https://nerdlypleasures.blogspot.com/2012/04/unique-pc-hardware-game-support.html |website=Nerdly Pleasures}}</ref><ref>{{cite web | url=https://www.youtube.com/watch?v=U4Ij3Ak7tak | title=Epson Equity 1e | website=YouTube | date=4 August 2015 }}</ref><ref>{{cite web | url=https://www.youtube.com/watch?v=YFih3TTpRR0 | title=Epson Equity 1e a second look | website=YouTube | date=23 May 2022 }}</ref><ref>{{cite web |last=Sokół |first=Radosław |date=26 December 2020 |title=The secret story of MCGA |url=https://www.swiat-owocow.pl/lang/en/1285.html |website=Świat Owoców}}</ref>

The MCGA supports all CGA display modes plus {{resx|640x480}} monochrome at a refresh rate of 60 Hz, and {{resx|320x200}} with 256 colors (out of an 18-bit RGB palette of 262,144) at 70 Hz.<ref>{{Cite book |last=Austerlitz |first=Howard |url=https://books.google.com/books?id=u62jBQAAQBAJ&dq=Multi-Color+Graphics+Array+MCGA&pg=PA79 |title=Data Acquisition Techniques Using PC |date=2014-06-28 |publisher=Academic Press |isbn=978-1-4832-9473-5 |pages=79 |language=en}}</ref><ref name=":1" /><ref name=":0" /> The display adapter uses a DE-15 connector, sometimes referred to as 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 uses 15-pin analog connectors. The PS/2 chipset's limited abilities prevent 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 of this display adapter was Epson, in the Equity Ie and 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 Ie - 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/ |website=The Silicon Underground}}</ref>

==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 {{resx|320x200}} 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 either forced to fall back to four-color CGA mode, the two-color CGA mode (or never run at all) due to the incompatibility with EGA video modes ({{resx|320x200}}, {{resx|640x200}}, or {{resx|640x350}}, all in 16 colors). 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 the MCGA's {{resx|320x200}} 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 ({{resx|640x480}} monochrome, which would also support {{resx|640x400}} and {{resx|640x350}} with some letterboxing) resolution mode in an acceptable fashion. An alternative approach used by a small number of (generally earlier) games was to use four-color CGA assets but make use of the adaptor's ability to freely change the palette for a slightly enhanced appearance.

==Output capabilities== MCGA offered:<ref name=":1" /><ref name=":0" /> *'''{{resx|640x480}} monochrome''' (mode 11h) *'''{{resx|320x200}} in 256 colors''' (from a palette of 262,144; mode 13h)

CGA compatible modes: *'''{{resx|40x25}} text mode''' with 8×8 pixel font (effective resolution of {{resx|320x200}}; mode 0/1h) *'''{{resx|80x25}} text mode''' with 8×8 pixel font (effective resolution of {{resx|640x200}}; mode 2/3h) *'''{{resx|320x200}} in four colors''' from a 16 color hardware palette with a pixel aspect ratio of 1:1.2. (mode 4/5h) *'''{{resx|640x200}} in two colors''' with a pixel aspect ratio of 1:2.4 (mode 6h)

==References== {{Reflist}} * {{cite book |first=Scott |last=Mueller |title=Upgrading and Repairing PCs |edition=Second |publisher=Que Books |year=1992 |isbn=0-88022-856-3 |url-access=registration |url=https://archive.org/details/upgradingrepairi0000muel_2ndedition }}

Category:Computer display standards Category:IBM PS/2 Multi-Color Graphics Adapter Category:Computer-related introductions in 1987