#include <stdio.h>

typedef unsigned char byte;

#define WAIT( port, flag )	while ( (inp(port)&flag) != 0 )

#define	COMDPORT   0x331		/* MPU-401 Command Port on IBM */
#define	STATPORT   0x331		/* MPU-401 Status Port on IBM */
#define	DATAPORT   0x330		/* MPU-401 Data I/O Port on IBM */
#define	DRR        0x40			/* Mask for Data Read Reg. Bit */
#define	DSR        0x80			/* Mask for Data Set Ready Bit */
#define	ACK        0xFE			/* MPU-401 Acknowledge Response */
#define	MASKFLIP   0xFF			/* WAIT Function Bit Mask XOR */
#define	MPURESET   0xFF			/* MPU-401 Total Reset Command */
#define	UARTMODE   0x3F			/* MPU-401 "Dumb UART Mode" */
#define	NOTEON1    0x90			/* MIDI Note On for Channel 1 */
#define	VELOCITY   64			/* MIDI Medium Key Velocity */
#define	NOTEOFF    0			/* 0 Velocity = Note Off */
#define	FIRSTNOTE  36			/* First note synth can play */
#define	LASTNOTE   96			/* Last note synth can play */

/***************************************************************************
 *                       I N I T I A L I Z A T I O N                       *
 ***************************************************************************/

RstMPU()
{
	int a;

	/* Clear Display */

	outp( COMDPORT, MPURESET );	/* Send MPU-401 RESET Command */
	a = inp( DATAPORT );		/* Dummy read to clear buffer */
	WAIT( STATPORT, DRR );		/* wait for port ready */
	outp( COMDPORT, UARTMODE );	/* Set MPU-401 "Dumb UART" Mode */
	a = inp(DATAPORT);		/* Dummy Read to clear buffer */
	WAIT( STATPORT, DSR );		/* Wait for "UART" port ready - */
        printf ("Interface init\n");    /*  Really crucial! */
}

/***************************************************************************
 *                         M A I N   P R O G R A M                         *
 ***************************************************************************/
snd (i)
	int i;

{
	int a;

	outp (DATAPORT, i);
	a=inp(DATAPORT);  /* dummy read */
        WAIT (STATPORT, DRR);
        printf ("0x%02x\b\b\b\b", i); 
}

main(argc, argv)
	int argc;
	char *argv[];
{
	FILE *fp;
	int i;
	int cksum;
	int ch;

        RstMPU();

	if (argc != 2)
	{
	  printf ("Usage: dload <filename>\n");
	  exit(-1);
	}

	printf ("Download %s...", argv[1]);

	if ((fp = fopen(argv[1], "rb")) == NULL)
	{
	   printf ("cannot open\n");
	   exit(-1);
	}

	cksum = 0;

        ch = fgetc(fp);

	while ((ch & 0xff)!=0xf7)
	{
	   snd (ch);
	   cksum++;
	   ch = fgetc(fp);
	}

	snd ((int)0xF7);
	cksum++;

	printf ("\n Done - sent %d bytes\n", cksum);
}