Editing Enhanced Graphics Adapter (section)

== Hardware design ==
[[File:IBM_5151,_5153,_5154_monitors.jpg|alt=|thumb|IBM MDA, CGA and EGA monitors, all supported by the EGA card]]
The original IBM EGA was an 8-bit PC [[Industry Standard Architecture|ISA]] card with 64&nbsp;KB of onboard [[Random-access memory|RAM]]. An optional [[Expansion card|daughter-board]] (the ''Graphics Memory Expansion Card'') provided a minimum of 64&nbsp;KB additional RAM, and up to 192 KB if fully populated with the ''Graphics Memory Module Kit''.<ref>{{Cite book |url=https://ibm.retropc.se/ibm_ega/IBM%20EGA%20-%20Installation%20Instructions.pdf |title=IBM EGA Installation Instructions |pages=9, 10, 11 |access-date=2020-08-15 |archive-date=2022-02-11 |archive-url=https://web.archive.org/web/20220211184437/https://ibm.retropc.se/ibm_ega/IBM%20EGA%20-%20Installation%20Instructions.pdf |url-status=dead }}</ref> Without these upgrades, the card would be limited to four colors in 640&nbsp;×&nbsp;350 mode.<ref>{{Cite book |url=http://minuszerodegrees.net/oa/OA%20-%20IBM%20Enhanced%20Graphics%20Adapter.pdf |title=IBM Enhanced Graphics Adapter manual |pages=7}}</ref>

Output was via direct-drive [[RGB color model|RGB]],<ref>{{Cite book|url=http://minuszerodegrees.net/oa/OA%20-%20IBM%20Enhanced%20Graphics%20Adapter.pdf |title=IBM Enhanced Graphics Adapter manual |pages=83}}</ref> as with the CGA, but no [[composite video]] output was included.<ref>{{cite journal |last=Hart |first=Glenn A. |date=December 25, 1984 |title=IBM Sets a New Standard |url=https://books.google.com/books?id=azbgSlPdJawC&pg=PA173 |journal=PC Magazine |publisher=Ziff-Davis Publishing |volume=3 |issue=25 |page=173}}</ref> MDA and CGA monitors could be driven, as well as newly released enhanced color monitors for use specifically with EGA.<ref name=":3">{{Cite book |url=http://minuszerodegrees.net/oa/OA%20-%20IBM%20Enhanced%20Graphics%20Adapter.pdf |title=IBM Enhanced Graphics Adapter manual |pages=5, 6, 7}}</ref>

EGA-specific monitors used a [[Dual-sync monitor|dual-sync]] design which could switch from the 15.7&nbsp;kHz of 200-line modes to 21.8&nbsp;kHz for 350-line modes.<ref name=":3" />[[File:KL Genoa EGA.jpg|thumb|A non-IBM EGA card]]

Many EGA cards have [[DIP switch]]es on the back of the card to select the monitor type. If CGA is selected, the card will operate in 200-line mode and use 8×8 characters in [[text mode]]. If EGA is selected, the card will operate in 350-line mode and use 8×14 text.

Some third-party cards using the EGA specification were sold with the full 128&nbsp;KB of RAM from the factory, while others included as much as 256&nbsp;KB to enable multiple graphics pages, multiple text-mode [[Character encoding|character sets]], and large [[scrolling]] displays.<ref name=":0" /> A few third-party cards, such as the [[ATI Technologies]] [[EGA Wonder]], built on the EGA standard to additionally offer features such as extended graphics modes as high as {{resx|800×560}} and automatic monitor type detection.<ref>{{Cite news |date=August 17, 1987 |title=EGA Wonder Any Software. Any Monitor. Any Time. 800x560 640x480 |pages=41 |work=InfoWorld |url=https://books.google.com/books?id=2jsEAAAAMBAJ&q=infoworld+ATI+EGA+400+line&pg=PA41}}</ref>