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Mail Archives: djgpp/1998/01/04/20:49:59

From: qball1723 AT aol DOT com (QBall1723)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: What is __djgpp_conventional_base ??
Date: 5 Jan 1998 01:33:37 GMT
Lines: 38
Message-ID: <19980105013300.UAA08128@ladder02.news.aol.com>
NNTP-Posting-Host: ladder02.news.aol.com
Organization: AOL http://www.aol.com
References: <34A97AB5 DOT 14FD6E93 AT stayfree DOT co DOT uk>
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

>Hi,
>
>    I was trying to access the video ram using
>        unsigned char *videoptr = (unsigned char *)0xA0000;
>
>    (in VBE1.2 640x480x256)
>
>    and it didn't work, so I downloaded a tutorial on video memory under
>djgpp, and it used the line
>
>        unsigned char *videoptr = (unsigned char *)0xA0000 +
>__djgpp_conventional_base;
>
>    What is __djgpp_conventional_base? There is no mention of it in
>Rhide's syntax help and the document didn't explain it.
>
>    Also, which is the FASTEST way to access the video memory, enabling
>near pointers or emulating far pointers?? (or is there a better way)
>
>    Please note that i'm using VBE1.2 so I can't use linear frames in my
>graphics modes.
>
>

__djgpp_conventional_base is something you need to add to your pointers if you
want to use nearpointers....

I looked for an explaination as well - in the RHIDE online help... I found
reference to it in the _djgpp_nearptr_enable

Near pointers are faster... at least I THINK so...

Keep in mind it disables all memory protection.


Jim the loiterer (wannabe PC game/graphics developer)
http://members.aol.com/qball1723/index.htm
[please don't hate me because I pay too much for poor internet service!!]

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