Path: utzoo!utgpu!water!watmath!clyde!att!rutgers!mailrus!uflorida!novavax!proxftl!markd
From: markd@proxftl.UUCP (Mark Davidson)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Microsoft Quickc - Pointers to arbitrary memory location
Message-ID: <694@proxftl.UUCP>
Date: 2 Sep 88 14:01:34 GMT
References: <666@dogie.edu>
Reply-To: markd@proxftl.UUCP (Mark Davidson)
Organization: Proximity Technology, Ft. Lauderdale
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In article <666@dogie.edu> dorl@vms.macc.wisc.edu (Michael Dorl - MACC) writes:
>I've been trying to reference screen memory directly from Quickc.
>The stuff I've tried looks something like this
>
>  char far *p;
>  long i;
>
>  p = (char far *)0xb8000;
>  for (i=0; i<0x8000; i++) {
>   *p = '\000';
>   p++;
>  }
(I hope this is right!)  One problem I see (at least it's different from the
way I tried it) is your assignment to p.  If your screen memory starts at
0xb8000 (this is an absolute address), then the value you assign to p must
be given in a variation of segment:offset format.  In other words, say

	p = (char far *) 0xb8000000;

and then dereference p to access a location in screen memory.  I've done this
in Quick C to implement pull-down menus, windows, etc (i.e., quick and dirty
prototyping).
-- 
  In real life: Mark E. Davidson       uflorida!novavax!proxftl!markd
  Proximity Technology Inc., 3511 NE 22nd Ave, Ft. Lauderdale FL, 33308
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