93 lines
2.4 KiB
C
Executable file
93 lines
2.4 KiB
C
Executable file
/*
|
|
THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
|
|
SOFTWARE CORPORATION ("PARALLAX"). PARALLAX, IN DISTRIBUTING THE CODE TO
|
|
END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
|
|
ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
|
|
IN USING, DISPLAYING, AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
|
|
SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
|
|
FREE PURPOSES. IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
|
|
CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES. THE END-USER UNDERSTANDS
|
|
AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
|
|
COPYRIGHT 1993-1999 PARALLAX SOFTWARE CORPORATION. ALL RIGHTS RESERVED.
|
|
*/
|
|
|
|
#pragma off (unreferenced)
|
|
static char rcsid[] = "$Id: cdrom.c,v 1.1.1.1 2006/03/17 19:58:09 zicodxx Exp $";
|
|
#pragma on (unreferenced)
|
|
|
|
#include <dos.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
#include "dpmi.h"
|
|
|
|
typedef struct {
|
|
char unit;
|
|
ushort dev_offset;
|
|
ushort dev_segment;
|
|
} dev_list;
|
|
|
|
typedef struct _Dev_Hdr {
|
|
unsigned int dev_next;
|
|
unsigned short dev_att;
|
|
ushort dev_stat;
|
|
ushort dev_int;
|
|
char dev_name[8];
|
|
short dev_resv;
|
|
char dev_letr;
|
|
char dev_units;
|
|
} dev_header;
|
|
|
|
int find_descent_cd()
|
|
{
|
|
dpmi_real_regs rregs;
|
|
|
|
// Get dos memory for call...
|
|
dev_list * buf;
|
|
dev_header *device;
|
|
int num_drives, i;
|
|
unsigned cdrive, cur_drive, cdrom_drive;
|
|
|
|
memset(&rregs,0,sizeof(dpmi_real_regs));
|
|
rregs.eax = 0x1500;
|
|
rregs.ebx = 0;
|
|
dpmi_real_int386x( 0x2f, &rregs );
|
|
if ((rregs.ebx & 0xffff) == 0) {
|
|
return -1; // No cdrom
|
|
}
|
|
num_drives = rregs.ebx;
|
|
|
|
buf = (dev_list *)dpmi_get_temp_low_buffer( sizeof(dev_list)*26 );
|
|
if (buf==NULL) {
|
|
return -2; // Error getting memory!
|
|
}
|
|
|
|
memset(&rregs,0,sizeof(dpmi_real_regs));
|
|
rregs.es = DPMI_real_segment(buf);
|
|
rregs.ebx = DPMI_real_offset(buf);
|
|
rregs.eax = 0x1501;
|
|
dpmi_real_int386x( 0x2f, &rregs );
|
|
cdrom_drive = 0;
|
|
_dos_getdrive(&cdrive);
|
|
for (i = 0; i < num_drives; i++) {
|
|
device = (dev_header *)((buf[i].dev_segment<<4)+ buf[i].dev_offset);
|
|
_dos_setdrive(device->dev_letr,&cur_drive);
|
|
_dos_getdrive(&cur_drive);
|
|
if (cur_drive == device->dev_letr) {
|
|
if (!chdir("\\descent")) {
|
|
FILE * fp;
|
|
fp = fopen( "saturn.hog", "rb" );
|
|
if ( fp ) {
|
|
cdrom_drive = device->dev_letr;
|
|
fclose(fp);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
_dos_setdrive(cdrive,&cur_drive);
|
|
return cdrom_drive;
|
|
}
|
|
|