Path: utzoo!attcan!uunet!lll-winken!ames!killer!chasm
From: chasm@killer.DALLAS.TX.US (Charles Marslett)
Newsgroups: comp.sys.ibm.pc
Subject: Re: VGA,EGA,CGA question
Summary: VGA is a superset of EGA
Message-ID: <6766@killer.DALLAS.TX.US>
Date: 13 Jan 89 06:12:14 GMT
References: <13017@duke.cs.duke.edu> <639@atanasoff.cs.iastate.edu> <2323@nunki.usc.edu>
Organization: The Unix(R) Connection, Dallas, Texas
Lines: 14



Virtually all EGA software will run perfectly on a VGA (the exceptions
are limited to a few programs that are very much optimized for a special
environment -- high speed graphics terminal emulation programs, for
example).  To a lesser extent, the same applies to running CGA software.
The VGA has a bit in CRTC register 0x11 that is used to disable writes
to several of the registers that CGA software often writes to... the
effect is that often such non-EGA compatible software can be made to work
much better on a VGA than on an EGA (as opposed to the autoswitching EGAs
like ATI's that run in a real CGA mode when such software is invoked).

Charles
chasm@killer.dallas.tx.us