#include "ppilib.c"

#define NP	500
double	lastval[NP];

void main()
{
double  t, v, timer=0.0;
int	k;
char	ss[20], old[20];

initTimer();
initialize();
setWorld(0, -5000, NP, 5000);
drawGrid("Time","Voltage (mV)");
setwritemode(1);

for(;;)
    {
    v = minus5000To5000();
    if( (v < 0) || ( v > 1000) ) continue;	/* trigger value */
    markStart();

	for(k=0 ; k < NP; ++k)	/* do one round */
	{
	drawPoint(k, lastval[k], BLACK);
	lastval[k] = v = minus5000To5000();
	drawPoint(k, v, WHITE);
/*	wait(timer);
*/	}

    t = elapsedTime();
    sprintf(ss,"%4.2f mS/div",t*100);
    setcolor(BLACK);
    drawText(0.10*NP, -5800.0, old);
    strcpy(old,ss);
    setcolor(RED);
    drawText(0.10 * NP, -5800.0, ss);

    if(kbhit())
	{
	int c = getch();
	if(!c) c = getch();	/* get extended key pressed */
	if(c == 27) break;
	if(c == LEFT) if(timer < 10000) ++timer;
	if(c == RIGHT) if(timer > 1) --timer;
	}
    }

closegraph(); 		/* Return the system to text mode	*/
}