#include "byte.h"void byte_copy(to,n,from)register char *to;register unsigned int n;register char *from;{  for (;;) {    if (!n) return; *to++ = *from++; --n;    if (!n) return; *to++ = *from++; --n;    if (!n) return; *to++ = *from++; --n;    if (!n) return; *to++ = *from++; --n;  }}