#include <stdio.h>
#include <stdlib.h>
#include <dos.h>
#include <conio.h>
#include "v25.h"

#define  STEPPORT     0x7900	/* STEPPING MOTOR PORT */
#define  OUTPORT0     0x7880

#define PRE_SCALE	10

void
main(void)
{
	unsigned char speed, ch;
	unsigned char step = 1;
	unsigned char led  = 1, prescaler = PRE_SCALE, photo;
	int direction = 0;
	
	do {
		printf("\nInput Speed 1 - 9 : ");
		speed = getch();
		printf("%c", speed);
	} while ((speed < '1') || (speed > '9'));
	printf("\n");
	
	for (;;) {
		photo = (peekb(V25_IRAM, V25_P1) & 0x20) ? 0x80 : 0xC0;

		outportb(OUTPORT0, led | photo);
		outportb(STEPPORT, step);
		delay((0x3B - speed) * 10);
		if (!(--prescaler))
			prescaler = PRE_SCALE;
		if (direction) {
			step <<= 1;
			if (step == 0x10)
				step = 1;
			if (prescaler == PRE_SCALE) {
				led <<= 1;
				if (led == 0x40)
					led = 1;
			}
		} else {
			step >>= 1;
			if (step == 0)
				step = 0x08;
			if (prescaler == PRE_SCALE) {
				led >>= 1;
				if (led == 0)
					led = 0x20;
			}
		}
		if (kbhit()) {
			if ((ch = getch()) == ' ')
				direction = !direction;
			else
				if ((ch >= '1') && (ch <= '9'))
					speed = ch;
				else
					break;
		}
	}
	outportb(STEPPORT, 0);
	outportb(OUTPORT0, 0);
}