/*
   =============================================================================
	puteq.c -- output functions for the LMC835 EQ chip on the Buchla 700
	Version 3 -- 1987-12-10 -- D.N. Lynx Crowe
   =============================================================================
*/

#define	TESTER		0

#if	TESTER
#define	MAXLINE		4
#endif

#include "ram.h"

#define	EQ_STB		0x04
#define	EQ_DAT		0x08
#define	EQ_CLK		0x10

#define	EQ_IDL		(EQ_STB | EQ_CLK)
#define	EQ_MASK		(EQ_STB | EQ_CLK | EQ_DAT)

#define	EQ_A6DB		0x20
#define	EQ_B6DB		0x10

#define	EQ_6DB		(EQ_A6DB | EQ_B6DB)

#define	EQ_ADD		0x40

#define	PSG_ADDR	0
#define	PSG_READ	0
#define	PSG_WRIT	2

#define	PSG_IOEN	7
#define	PSG_IDLE	0xBF

#define	PSG_PRTB	15

/* 
*/

#if	TESTER
char	cmdline[32];
#endif

int8_t eqgaint[] = {

	0x00,	/*  0 db */
	0x20,	/*  1 db */
	0x10,	/*  2 db */
	0x08,	/*  3 db */
	0x04,	/*  4 db */
	0x02,	/*  5 db */
	0x12,	/*  6 db */
	0x2A,	/*  7 db */
	0x16,	/*  8 db */
	0x01,	/*  9 db */
	0x29,	/* 10 db */
	0x2D,	/* 11 db */
	0x2F	/* 12 db */
};

/* 
*/

void puteq(int8_t byte)
{
	register int16_t i;
	register int8_t *psg;
	register int8_t eqdata;

	psg = &io_tone;

	*(psg + PSG_ADDR) = PSG_IOEN;		/* setup PSG I/O controls */
	*(psg + PSG_WRIT) = PSG_IDLE;

	*(psg + PSG_ADDR) = PSG_PRTB;		/* setup EQ control lines */
	eqdata = EQ_IDL | (*(psg + PSG_READ) & ~EQ_MASK);

	for (i = 0; i < 8; i++) {		/* send out 8 bits */

		if (byte & 1)			/* setup data line from LSB */
			eqdata |= EQ_DAT;	/* "1" */
		else
			eqdata &= ~EQ_DAT;	/* "0" */

		eqdata &= ~EQ_CLK;		/* set clock low */

		*(psg + PSG_ADDR) = PSG_PRTB;
		*(psg + PSG_WRIT) = eqdata;

		eqdata |= EQ_CLK;		/* set clock high */

		*(psg + PSG_ADDR) = PSG_PRTB;
		*(psg + PSG_WRIT) = eqdata;

		byte >>= 1;			/* shift next bit into LSB */
	}

	eqdata &= ~EQ_STB;			/* set strobe low */

	*(psg + PSG_ADDR) = PSG_PRTB;
	*(psg + PSG_WRIT) = eqdata;

	eqdata |= EQ_STB;			/* set strobe high */

	*(psg + PSG_ADDR) = PSG_PRTB;
	*(psg + PSG_WRIT) = eqdata;
}

/* 
*/

void sendeq(int8_t band, int8_t gain)
{
	puteq(band);
	puteq(gain);
}

int8_t gain2eq(int16_t gain)
{
	register int8_t eqdat;

	if (gain > 0)
		eqdat = eqgaint[gain] | EQ_ADD;
	else
		eqdat = eqgaint[-gain];

	return(eqdat);
}

/* 
*/

#if	TESTER

char	ahex[] = "0123456789abcdefABCDEF";

/*
   ============================================================================
	xdtoi -- convert hex ASCII to an int digit
   ============================================================================
*/

int
xdtoi(c)
register int c;
{
	register int i;
	register char *ap = &ahex[0];

	for (i = 0; i < 22; i++)
		if (c EQ *ap++)
			if (i >15)
				return(i - 6);
			else
				return(i);

	return(-1);
}

/* 
*/

main()
{
	short	rc, c, j;
	register long	temp;
	char	gain, band;
	register char	*aptr;

	printf("\n\nBuchla 700 EQ chip test -- Enter data in hex\n\n");

	do {

		printf("Band = ");

		rc = getln(CON_DEV, MAXLINE, cmdline);

		if (rc EQ A_CR) {

			printf("\n");

			temp = 0L;
			aptr = cmdline;

			if (A_CR EQ (*aptr & 0x00FF)) {

				xtrap15();
				continue;
			}

			if (CTL('G') EQ (*aptr & 0x00FF)) {

				while (0 EQ BIOS(B_RDAV, CON_DEV))
					sendeq(band, gain);

				BIOS(B_GETC, CON_DEV);
				continue;
			}

			while (isxdigit(c = *aptr++))
				temp = (temp << 4) + xdtoi(c);

			if (temp > 255) {

				printf("\nInput must be < 100\n\n");
				continue;
			}

			band = (char)(temp & 0x000000FFL);

		} else {

			printf("Huh ?\n\n");
			continue;
		}
/* 
*/
		printf("Gain = ");

		rc = getln(CON_DEV, MAXLINE, cmdline);

		if (rc EQ A_CR) {

			printf("\n");

			temp = 0L;
			aptr = cmdline;

			if (A_CR EQ (*aptr  & 0x00FF)) {

				xtrap15();
				continue;
			}

			while (isxdigit(c = *aptr++))
				temp = (temp << 4) + xdtoi(c);

			if (temp > 255) {

				printf("\nInput must be < 100\n\n");
				continue;
			}

			gain = (char)(temp & 0x000000FFL);

		} else {

			printf("Huh ?\n\n");
			continue;
		}

		sendeq(band, gain);
		printf("\n");

	} while (1);
}

#endif