lsfs_16-bit/driver/disk.h

int disk_service_read_data_from_disk(index, file_block_size, data_buffer, data_buffer_segment) 
long* index; 
long file_block_size; 
void* data_buffer;
int data_buffer_segment;
{
    //fseek ( disk, (index * SECTOR_SIZE ), SEEK_SET ); // SEEK_SET start offset at index 0 and move 1 * SECTOR_SIZE, and write here.
    //int read = fread(data_buffer, 1, (file_block_size * SECTOR_SIZE), disk);
    //return read;
	#asm
	lsfs_load_data:
    mov dl, [global_disk_identifier]
    mov WORD [DAPACK.lba_addr_dw_low], ax
    mov WORD [DAPACK.blkcnt],          0x01  
    mov WORD [DAPACK.db_addr_segment], bx
    mov WORD [DAPACK.db_addr_offset],  FSCI
    mov si, DAPACK                          ; address of "disk address packet"
    mov ah, 0x42                            ; READ
    mov dl, [global_disk_identifier] 
    int 0x13
	
	DAPACK:
	  .dap_Size:         db  0x10   ; This is always 16 bytes (0x10)
	  .rev_byte:         db  0x0    ; reserved byte, should always be zero
	  .blkcnt:           dw  0x0    ; int 13 resets this to # of blocks actually read/written
	  .db_addr_offset:   dw  0x0    ; memory buffer destination address (0:7c00)
	  .db_addr_segment:  dw  0x0    ; in memory page zero
	  .lba_addr_dw_low:  dd  0x0    ; put the lba to read in this spot
	  .lba_addr_dw_high: dd  0x0    ; more storage bytes only for big lba's ( > 4 bytes )
	#endasm

}