#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <dos.h>

#define	INT2F	0x2f

void exit(int errno);


/*
 *  MSCDEX Substitue, setting alteration program.
 *
 *  Operation:
 *	This modifies the configuration of MSCSUB whilst it is loaded and 
 *	running. It allows:
 *	 	1. Drives to be added or deleted.
 *		2. Alteration of MSCDEX version number.
 *		3. To turn off MSCMON and pass calls to MSCDEX (if installed).
 *		4. To turn on MSCMON if turned off.
 *		5. Change Device Driver Name (eg MSCD000)
 *		6. Change Name of file containing data for MSCSUB functions
 *		    02h,03h,04h
 *
 *  Syntax:
 *	Run the program without arguments to check the command switches.
 *
 *  Compiler Used:
 *	Borland C++, 3.1
 *
 *  Compile: bcc -1 -ml mscmon.c
 *
 *  Test History:
 *	Works okay on 486's and 386's. I haven't tried it out on any 286's yet.
 *
 *  Author: 	Colin Ian King, Templeman Library, University of Kent.
 *
 *  Modification Record:
 *
 *	01/03/93	Creation.
 */

void
syntax(void)
{
	fprintf(stderr,"\nUsage: mscmod -a drive ...   add drives\n");
	fprintf(stderr,"       mscmod -r drive ...   remove drives\n");
	fprintf(stderr,"       mscmod -v version     modify mscdex version number\n");
	fprintf(stderr,"		eg: mscmod -v 0210   (version 2.10)\n");
	fprintf(stderr,"       mscmod -mon           mscmon on\n");
	fprintf(stderr,"       mscmod -moff          mscmon off\n");
	fprintf(stderr,"       mscmod -name MSCxxxx  set name of device driver to MSCxxxx\n");
	fprintf(stderr,"       mscmod -file file     set name of data file for functions 02h,03h,04h\n");
}


void
main(int argc, char** argv)
{
	int i;

	char buffer[64];
	union  REGS inregs,outregs;
	struct SREGS segregs;

	fprintf(stdout,"MSCSUB Modifier by cik@ukc.ac.uk, ");

	if (argc < 2) {
		syntax();
		exit(1);
	}
	/*
	 *    bx sub-command:
	 *	00,  Install drive in cx, eg cx=0, Drive A,
	 *				     cx=1, Drive B, etc
 	 *	01,  Remove drive in cx,  eg cx=0, Drive A, etc
	 *	02,  Set mscdex version number, eg cx = 0x020a => 2.10
	 *	03,  Turn off this mscsub, pass over to normal handler
	 *	04,  Turn on mscsub.
	 */

	if (!strcmp(argv[1],"-a")) {
		for (i=2;i<argc;i++) {
			if (!isalpha(argv[i][0])) {
				fprintf(stderr,"\n%c is not a drive\n",argv[i][0]);
				exit(1);
			}
			_CX = (char)(argv[i][0] - 'A');
			_AX = 0x15ff;
			_BX = 0x00;
			geninterrupt(INT2F);
		}
		exit(0);
	}
	if (!strcmp(argv[1],"-r")) {
		for (i=2;i<argc;i++) {
			if (!isalpha(argv[i][0])) {
				fprintf(stderr,"\n%c is not a drive\n",argv[i][0]);
				exit(1);
			}
			_CX = (char)(argv[i][0] - 'A');
			_AX = 0x15ff;
			_BX = 0x01;
			geninterrupt(INT2F);
		}
		exit(0);
	}
	if (!strcmp(argv[1],"-v")) {
		sscanf(argv[2],"%4x",&i);
		_AX = 0x15ff;
		_BX = 0x02;
		_CX = i;
		geninterrupt(INT2F);
		exit(0);
	}
	if (!strcmp(argv[1],"-moff")) {
		_AX = 0x15ff;
		_BX = 0x03;
		_CX = i;
		geninterrupt(INT2F);
		exit(0);
	}
	if (!strcmp(argv[1],"-mon")) {
		_AX = 0x15ff;
		_BX = 0x04;
		_CX = i;
		geninterrupt(INT2F);
		exit(0);
	}
	if (!strcmp(argv[1],"-name")) {
		strncpy(buffer,argv[2],8);
		buffer[8] = '\0';
		printf("%s\n",buffer);
		inregs.x.ax = 0x15ff;
		inregs.x.bx = 0x05;
		inregs.x.cx = FP_OFF(buffer);
		segregs.es  = FP_SEG(buffer);
		int86x(0x2f, &inregs, &outregs, &segregs);
		geninterrupt(INT2F);
		exit(0);
	}
	if (!strcmp(argv[1],"-file")) {
		strncpy(buffer,argv[2],64);
		buffer[64] = '\0';
		printf("%s\n",buffer);
		inregs.x.ax = 0x15ff;
		inregs.x.bx = 0x06;
		inregs.x.cx = FP_OFF(buffer);
		segregs.es  = FP_SEG(buffer);
		int86x(0x2f, &inregs, &outregs, &segregs);
		geninterrupt(INT2F);
		exit(0);
	}

	syntax();
	exit(1);
}