DISK.C
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/* DISK.C illustrates low-level disk access using functions:
* _bios_disk _dos_getdiskfree
*
*/
#include <stdio.h>
#include <conio.h>
#include <bios.h>
#include <dos.h>
#include <stdlib.h>
char _far diskbuf[512];
void main( int argc, char *argv[] )
{
unsigned status = 0, i;
struct diskinfo_t di;
struct diskfree_t df;
unsigned char _far *p, linebuf[17];
if( argc != 5 )
{
printf( " SYNTAX: DISK <driveletter> <head> <track> <sector>" );
exit( 1 );
}
if( (di.drive = toupper( argv[1][0] ) - 'A' ) > 1 )
{
printf( "Must be floppy drive" );
exit( 1 );
}
di.head = atoi( argv[2] );
di.track = atoi( argv[3] );
di.sector = atoi( argv[4] );
di.nsectors = 1;
di.buffer = diskbuf;
/* Get information about disk size. */
if( _dos_getdiskfree( di.drive + 1, &df ) )
exit( 1 );
/* Try reading disk three times before giving up. */
for( i = 0; i < 3; i++ )
{
status = _bios_disk( _DISK_READ, &di ) >> 8;
if( !status )
break;
}
/* Display one sector. */
if( status )
printf( "Error: 0x%.2x\n", status );
else
{
for( p = diskbuf, i = 0; p < (diskbuf + df.bytes_per_sector); p++ )
{
linebuf[i++] = (*p > 32) ? *p : '.';
printf( "%.2x ", *p );
if( i == 16 )
{
linebuf[i] = '\0';
printf( " %16s\n", linebuf );
i = 0;
}
}
}
exit( 1 );
}