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

void main()
{
	int major,minor;
	union REGS regs;	//required for making DOS calls

	regs.h.al=1;		//Get version number
	regs.h.ah=0x30;		//Get version function 30h
	int86(0x21,&regs,&regs);//Call DOS

	major=regs.h.al;	//get major version no.
	minor=regs.h.ah;	//get minor version no.

	printf("This is DOS version %i, release %i\n",major,minor);
}