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

/*
 * Reliable NEC V20 detection
 * Written by Anthony V. Ingenoso
 */

void main(void)
{
   _BX = 0x00ff;
   _AX = 0x00ff;

   __emit__(0xd4, 16);  /* mutant AAM (splits nibbles in AL into 0F0F in AX */
   __emit__(0xd5, 16);  /* mutant AAD (glue nibbles back into 00FF in AX    */

   if (_AX != _BX)
      puts("This is a V20 CPU\n");
   else
      puts("This isn't a V20\n");
}
