/**
    PC-MOS/386 Ver. 3.0 Interface Functions
    Copyright (C) 1988, 1989 More Custom Software. All rights reserved.
    Written in Microsoft C ver. 5.1
    Copyright Microsoft Corporation, 1984-1987. All rights reserved.

    - Description -
    Checks if the operating system is PC-MOS/386.

    - Return -
    0 if not PC-MOS/386.
    Version number if MOS.

**/
#include <dos.h>
#include <mos.h>

int ismos()
{
    union REGS inregs, outregs;
    int results;

    inregs.h.ah = 0x30;
    results = intdos(&inregs, &outregs);
    if (results != 0x1403)
	return(0);
    inregs.x.ax = 0x3000;
    inregs.x.bx = 0x3000;
    inregs.x.cx = 0x3000;
    inregs.x.dx = 0x3000;
    results = intdos(&inregs, &outregs);
    if (results != 0x1403)
	return(results);
    return(0);
}