Message-ID: <32A29911.5126@eepo.com.au>
Date: Mon, 02 Dec 1996 16:53:37 +0800
From: Robert Hill <Rob DOT Hill AT eepo DOT com DOT au>
MIME-Version: 1.0
To: djgpp AT delorie DOT com
CC: Rob DOT Hill AT eepo DOT com DOT au
Subject: Problems accessing system timer with nearptr.h
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

Dear Gurus.. 
The following function has been adapted from a book by Andre LaMothe on 
basic game programming.  For some reason it causes a segmentation fault 
and I can't figure out why.  My first assumption is that I have converted 
the address of the system timer incorrectly, but all of the video 
functions underwent the same transformation and seem to go OK.  The code 
is being compiled on DJGPP v 2 an run on an i486 DX4 100 (just in case 
this is useful)  


thankx for your help
robby


_________________________________________________________________________void Delay(int clicks)
{
// this function uses the internal time keeper timer i.e. the one that 
goes
// at 18.2 clicks/sec to to a time delay.  You can find a 32 bit value of
// this timer at 0000:046Ch

unsigned int *clock = (unsigned int *)0x0046C;

unsigned int now;

// get current time
__djgpp_nearptr_enable();
clock += __djgpp_conventional_base;
now = *clock;

// wait till time has gone past current time plus the amount we eanted to
// wait.  Note each click is approx. 55 milliseconds.

while(abs(*clock - now) < clicks){}
__djgpp_nearptr_disable();
} // end Delay 
_________________________________________________________________________

go32/v2 version 2.0 built Jan 23 1996 22:03:02
Usage: go32 coff-image [args]
Rename this to go32.exe only if you need a go32 that can run v2 binaries 
as
 well as v1 binaries (old makefiles).  Put ahead of the old go32 in your 
PATH.
DPMI memory available: 8 Kb
DPMI swap space available: 9772 Kb




CONFIG=Qemm
LOADHIDATA=C:\QEMM\LOADHI.RF
COMSPEC=C:\COMMAND.COM
BLASTER=A220 I5 D1 H5 P330 T6
SOUND=C:\DRIVERS\SB16
PATH=C:\WINDOWS;C:\DOS;C:\UUPC\BIN;D:\UTILS\ZIP;D:\UTILS\NORTON;D:\VIDEO\VIDDOS;C:\DJGPP\BIN;
DJGPP=c:/djgpp/djgpp.env
TEMP=C:\TEMP
PICNIX_SWITCHAR=-
TZ=WST-8
UUPCSYSRC=c:\uupc\uupc.rc
UUPCNEWS=c:\uupc\news
USER=ROB
HOME=c:\home\ROB
UUPCUSRRC=c:\home\ROB\personal.rc
SNEWSRC=c:\home\ROB\snews.rc
DEBUG=00
ANODE=Mr Gates' windowing environment's sacrificial goat
PROMPT=$p$g
windir=C:\WINDOWS