// Found in src/unix/V6/usr/source/s1/ed.c

/*
 * Get process ID routine if system call is unavailable.
 */
getpid()
{
        register f;
        int b[1];

        f = open("/dev/kmem", 0);
        if(f < 0)
                return(-1);
        seek(f, 0140074, 0);
        read(f, b, 2);
        seek(f, b[0]+8, 0);
        read(f, b, 2);
        close(f);
        return(b[0]);
}