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Article #5846Re: VGA memory access
From: Edwin Phillips
Date: Mon, 08 Apr 1991 07:50
Date: Mon, 08 Apr 1991 07:50
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1642 bytes
On a _standard_ VGA card with 256K, it is easy to access the first 64K of memory on the card with reads/writes to segment A000H in the PC memory map. Is it possible, however, to read/write to the rest of the memory on the card? If not, why? What is the other 192K used for? Why is it there? I know that on super-standard cards there is usually an extra register which controls some kind of window into the card's memory (at least it works this way with the Western Digital PVGA). Is there a similar control for _standard_ VGA cards? Ed /***************************************************************************/ /* Ed Phillips flaregun@chopin.udel.edu It's never impossible, */ /* (128.175.13.17) only highly unlikely. */ /* ed.phillips@mvs.udel.edu */ /* (128.175.13.24) */ /***************************************************************************/ /* University of Delaware Operations and Technical Services */ /***************************************************************************/
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arc1-ca.pugleaf.net!utzoo!attcan!uunet!elroy.jpl.nasa.gov!swrinde!zaphod.mps.ohio-state.edu!wuarchive!udel!brahms.udel.edu!flaregunReferences:
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Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!elroy.jpl.nasa.gov!swrinde!zaphod.mps.ohio-state.edu!wuarchive!udel!brahms.udel.edu!flaregun From: flaregun@brahms.udel.edu (Edwin Phillips) Newsgroups: comp.os.msdos.programmer Subject: Re: VGA memory access Summary: Clarification of previous question Message-ID: <20240@brahms.udel.edu> Date: 8 Apr 91 07:50:51 GMT References: <16863@chopin.udel.edu> Distribution: na Organization: University of Delaware Lines: 19