From: Charles Brasted <cbrasted AT physics DOT adelaide DOT edu DOT au>
Message-Id: <9603150414.AA13892@pilot.physics.adelaide.edu.au>
Subject: Suggestion for FAQ and int86 question.
To: djgpp AT delorie DOT com
Date: Fri, 15 Mar 1996 13:44:28 +0930 (CST)
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I recently posted a question, which had also plagued others, about the new
version not finding header files or crt0.o when compiling.

The FAQ identifies this problem, however it could perhaps add an additional
paragraph to remind people to be wary of stray spaces in the environment
settings.

As far as I can tell, I had let some stray spaces enter between the "set
djgpp" and the rest, which apparently was the source of the problem.  For
example I typed 
set djgpp = c:\djgpp\djgpp.env

instead of 
set djgpp=c:\djgpp\djgpp.env

in my autoexec.bat file.  Stupid I know, but this could be causing some
people grief.

I recall a warning of some sort somewhere in the documentation, however as
this problem manifests itself by the compiler "not finding header files"
etc, it might be worth an explicit mention in the FAQ under the section
regarding compiler problems.

Onto int86, this has had me stumped for a while.  I am using a familiar
routine to write to the screen, when I use the goto_xy(,) once, it works
fine.  However, when use the goto_xy routine twice in a row (as in the
following code), the screen clears, then the cursor flashes at the point
(20,20) then after the delay finishes, it moves to (10,10) and prints both
letters! As far as I can see it should print a letter 'c' at 20,20 and a 'd'
at 10,10.

What gives?  I hope someone can help me out, I don't fancy using
dosmemput...

code begins..


#include<stdio.h>
#include <dos.h>
#include <pc.h>

void goto_xy(int x, int y);
void pok(int x,  int y, char c);
void goto_xy(int x, int y)
{
union REGS r;
r.h.ah = 2;
r.h.dl = x;
r.h.dh = y;
r.h.bh = 0;
int86(0x10, &r, &r);
}

void pok(int x,  int y, char c)
{
	goto_xy(x,y);
	putchar(c);
}

void main(void)
{
	int count;
	system("cls");
	pok(10,10,'c');
	delay(10000);
	pok(20,20,'d');	
}