From: Christoph Kukulies <kuku AT gil DOT physik DOT rwth-aachen DOT de>
Message-Id: <199703031534.QAA12308@gil.physik.rwth-aachen.de>
Subject: Re: dpmi_int - any caveats?
In-Reply-To: <Pine.SUN.3.91.970303165321.9649C-100000@is> from Eli Zaretskii at "Mar 3, 97 04:58:03 pm"
To: eliz AT is DOT elta DOT co DOT il (Eli Zaretskii)
Date: Mon, 3 Mar 1997 16:34:32 +0100 (MET)
Cc: kuku AT gilberto DOT physik DOT RWTH-Aachen DOT DE, djgpp AT delorie DOT com
Reply-To: Christoph Kukulies <kuku AT gilberto DOT physik DOT rwth-aachen DOT de>
MIME-Version: 1.0
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> 
> On Mon, 3 Mar 1997, Christoph Kukulies wrote:
> 
> > I read djgppfaq.txt chapter 18.2 and as a result I thought I
> > had it working but the combo of my program and the driver
> > seems to be very unstable. I cannot invoke the program twice.
> 
> Please post more of your code (the fragment you showed seems OK).  For 
> example, how do you move data from and to the transfer buffer?

I appended the complete (quick and dirty) test program.

The driver requires that the X-Y-Z ccordinates are passed in a real mode
buffer:

Lower Address                      Higher Address
+---------------+----------------+--------------+
|x|x|x|x|x|x|x|x|y|y|y|y|y|y|y|y|z|z|z|z|z|z|z|z|
+---------------+----------------+--------------+

> 
> Also, can you see where does the program hang?  Is it in your code, or 
> inside the call to `__dpmi_int'?

My program (see below) is so straight that, if it hangs it can only
hang in their driver (or dpmi_int) - presumably :-)

> 
> > BTW, why is __tb>>4 anded with 0xffff? Since it is an address below 1MB
> > supplied by go32 the by 4 shifted value can never have any bits set
> > that would be masked off by 0xffff.
> 
> You forget the memory mapping.  The transfer buffer is physically indeed
> below 1MB mark, but its logical address is not guaranteed to have all the
> high bits zeroed. 
> 
> > Does it matter whether cwsdpmi is loaded once in autoexec (cwsdpmi -p)
> > or having it just in the path?
> 
> Shouldn't matter at all.
> 

--
Chris Christoph P. U. Kukulies kuku AT gil DOT physik DOT rwth-aachen DOT de
/*******************************************/
/*                                         */
/* Steuerprogramm fuer MPK3 3-Achsen Tisch */
/* Ch. Kukulies  25.2.97                   */
/*                                         */
/*******************************************/
#include <stdio.h>
#include "isl.h"
#include <dpmi.h>
#include <go32.h>

#define ESC 27
#define UP 328
#define DOWN 336
#define LEFT 331
#define RIGHT 333

#define _AL r.h.al
#define _AH r.h.ah
#define _BL r.h.bl
#define _BH r.h.bh
#define _CL r.h.cl
#define _CH r.h.ch
#define _DL r.h.dl
#define _DH r.h.dh

#define _CX r.x.cx
#define _DX r.x.dx

#define X(x)  *((char *)__tb) = x&0xff;*((char *)__tb+1)=(x>>8)&0xff;\
        *((char *)__tb+2) = (x>>16)&0xff;*((char *)__tb+3)=(x>>24)&0xff;
#define Y(x)  *((char *)__tb+4) = x&0xff;*((char *)__tb+1+4)=(x>>8)&0xff;\
        *((char *)__tb+2+4) = (x>>16)&0xff;*((char *)__tb+3+4)=(x>>24)&0xff;
#define Z(x)  *((char *)__tb+8) = x&0xff;*((char *)__tb+1+8)=(x>>8)&0xff;\
        *((char *)__tb+2+8) = (x>>16)&0xff;*((char *)__tb+3+8)=(x>>24)&0xff;

#define ISEL_CMD  __dpmi_int(0x78,&r)

main()
{ 
   int key;
   __dpmi_regs r;
   int xpos=0,ypos=0,zpos=0;
   isl_wakeup();
   r.x.ax=1;
   ISEL_CMD;
   printf("TREIBERVERSION  - %c%c%c%c%c%c\n",_BH,_BL,_CH,_CL,_DH,_DL);
   r.x.ax=2;
   ISEL_CMD;
   printf("TREIBERRESET OK (%d)\n",_AL);
   r.x.ax=9;   /* Teachin AUS */
   r.x.bx=0;
   ISEL_CMD;
   r.x.ax=6;
   r.x.bx=0;
   r.h.bl=7; /* x,y,z- Referenzfahrt */
   ISEL_CMD;
   printf("REFERENZFAHRT (%d)\n",_AL);
   printf("%08lhx %04x %02x\n",__tb,(__tb>>4)&0xffff,__tb&0x0f);fflush(stdout);
   r.x.ax=5;
   r.x.bx=0;
   ISEL_CMD;
   printf("TREIBERSTATUS (%d) cx=%08lx dx=%08lx\n",_AL,_CX,_DX);
   while(1){
      while (!(kbhit()))
          ;
      key=getkey();
      printf("key=%d\n",key);fflush(stdout);
      if(key==ESC)
	break;
      switch(key) {
	  case DOWN :
		zpos--;
		if(zpos<0)
			zpos=0;
		break;
          case UP :
		zpos++;
      		X(xpos);
      		Y(ypos);
      		Z(zpos);
      		r.x.ax=24;
      		r.x.cx=__tb&0x0f;
      		r.x.bx=(__tb>>4)&0xffff;
      		ISEL_CMD; 
		break;
	  case LEFT :
	  case RIGHT :
		break;
	  default :
		break;
       }
      printf("ABSOLUTE LINEARNORMALBEWEGUNG (%d)",_AL);
      fflush(stdout);
      r.x.ax=18;
      r.x.cx=__tb&0x0f;
      r.x.bx=(__tb>>4)&0xffff;
      ISEL_CMD;
      printf(" %08lx %08lx %08lx\n",
	   *((unsigned long *)__tb+0),
	   *((unsigned long *)__tb+1),
	   *((unsigned long *)__tb+2));
      fflush(stdout);
   }
   isl_sleep();
}  
isl_wakeup()
{
   __dpmi_regs r;
   r.x.ax=47;
   r.x.bx=0; /* wakeup modus */
   ISEL_CMD;
}
isl_sleep()
{
   __dpmi_regs r;
   r.x.ax=47;
   r.x.bx=1; /* sleep modus */
   ISEL_CMD;
}