/* INOUT.H */
/* Routines for D/A and encoder boards */

/* D/A routine */
void put_da(int channel,float voltage) {
	/* 2 channels numbered 0 and 1 */
	/* Routine returns the voltage within limits */
	#define daadd 0x304       /* Address of D/A board */                       
	#define umax 5.           /* Maximum D/A voltage */
	int dacount,msb,lsb;
	if (voltage>umax)  {voltage=umax;}     /* Output limiting */
	if (voltage<-umax) {voltage=-umax;}
	dacount=2048-(int)(voltage*2047./umax);
	msb=(int)(dacount/16);
	lsb=dacount-msb*16;
	lsb=lsb*16;
	outp(daadd+channel*2,lsb);
	outp(daadd+1+channel*2,msb); }

/* Encoder routines */
/* Board initialization & reset of counter */
void encoder_init() {
	#define encadd 0x310      /* Address of encoder board */
	outp(encadd+2,0x68);
	outp(encadd+2,0xC3);
	outp(encadd+2,0xA0);
	outp(encadd+2,0x05);
	outp(encadd+6,0x00); }
/* Routine to read the counter */
float get_encoder() {
	union returner {char in[3];long out;} rd;
	rd.out=0;
	outp(encadd+2,0x03);
	rd.in[0]=inp(encadd+4);
	rd.in[1]=inp(encadd+4);
	rd.in[2]=inp(encadd+4);
	if(rd.out>=8388608)rd.out=rd.out-16777216;
	return (float)(rd.out)*0.0031415926; }