/* Read OPUS
 * Convert a standard 40 Trk single side OPUS disk to a DOS file
 *
 *******************************************************
 * Roelof :      should have a flag for 1 or 2 sides
 *                                            a flag for 256 or 512 sect len  (16 or 8 sects)
 *                     'double step' adjusts the head movement for 40 tracks 
 *******************************************************
 * The disk is converted into a contigious file in the following layout:
 *    0..255    Track 0, Sector 0
 *  256..511    Track 0, Sector 1
 *  etc.
 */

#include <stdio.h>
#include <dos.h>
#include <stdlib.h>
#include <mem.h>
#include "readopus.h"

FILE *output ;

void set_double_step ( void )
{
	char far *drive_0_media_state;

	// Point into BIOS memory
	drive_0_media_state = MK_FP ( 0x0040,0x0090 );

	// enable "double stepping" bit
	*drive_0_media_state = ( *drive_0_media_state | 0x30 );
}


void set_sector_size ( int size )
{
	struct dpt far * far *param_table ;

	param_table = MK_FP (0000,0x0078);
	(*param_table)-> sector_size = size ;
}

int fd_recal (int drive)
{
	union REGS in, out;

	in.h.ah = 0x11;
	in.h.dl = drive;
	int86 (0x13, &in, &out);
	return out.h.ah;
}



int main()
{
	int i, side=0, track=0, sector=0 ;

	output = fopen ( "OPUS.OUT", "wb");
	if ( ! output )
		printf ("Unable to create file : OPUS.OUT");

	fd_recal ( 0 );

	set_sector_size ( SECTOR_256 );
	set_double_step ();

	for (track=0;track<40;track++) {
		for ( sector=0;sector<18;sector++) {
		   int result;

		   result = read_sectors (0, side, track, sector,1 );

		   printf ( "SIDE : %2d, TRACK : %2d, SECTOR : %2d = %d\n",
			     side,track,sector,result);
		}

	}

	set_sector_size ( SECTOR_512 );

	fclose (output);
}


void reset_fdc ()
// Issue int13, subfn 00 to reset the floppy controller
{
	union REGS in, out;

	in.h.ah = 0;
	in.h.dl = 0;
	int86 (0x13, &in, &out);
}


int read_sectors ( int drive, int side, int track, int sector,
		   int numsectors )
{
	union REGS in, out;
	struct SREGS seg;
	char *buffer;
	size_t num_written;

	buffer = malloc ( numsectors * BPS );
	if ( ! buffer ) {
		printf ( "Insufficient memory\n" );
		exit (1);
	}

	// Copy params
	in.h.ah = 2;
	in.h.dl = drive;
	in.h.dh = side;
	in.h.ch = track;
	in.h.cl = sector;
	in.h.al = numsectors;

	// Pass buffer address
	in.x.bx = FP_OFF ( buffer );
	seg.es  = FP_SEG ( buffer );

	int86x ( 0x13, &in, &out, &seg );

//      showbuffer (buffer)
	fwrite ( buffer, 1, numsectors * BPS, output );

	free (buffer);
	return out.h.ah;
}