VGA memory (Can I use more than 64k?)

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#315

From: Erik Johnson
Date: Fri, 07 Aug 1992 18:56

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I am new to the PC platform, but not new to graphics programming.

I have an ATI Graphics Ultra board with 1 meg of memory.  The program that I
am writing is for animation so I have decided on using the 320x200 256 color
mode (no incompatable SVGA headaches).

I understand that you can access video memory directly by writing to address
$A0000 and up.  Can I use more than the 64k though?  How can I access the
rest of the 1 meg of video RAM?  According to the books I have you can have
multiple pages, but mode 19 video only allows for 1 page.  I want atleast
2 pages to allow for double buffering.

I have no problems using the most direct method (ie. assembly + direct
register alterations), and in fact would prefer to do so for speed reasons.

I just noticed that all my paragraphs start with I.

Any help would be most appreciated.

Thank you,

   Erik R Johnson
   erik@microware.com

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Message-ID: <1992Aug7.185640.12772@microware.com>

Path: arc1-ca.pugleaf.net!sparky!uunet!mcrware!erik

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Newsgroups: comp.os.msdos.programmer
Path: arc1-ca.pugleaf.net!sparky!uunet!mcrware!erik
From: erik@microware.com (Erik Johnson)
Subject: VGA memory (Can I use more than 64k?)
Message-ID: <1992Aug7.185640.12772@microware.com>
Sender: news@microware.com
Nntp-Posting-Host: zeppo
Organization: Microware Systems Corp., Des Moines, Iowa
Date: Fri, 7 Aug 1992 18:56:40 GMT
Lines: 23