130KB 19KB 32KB bijectively blit bltj bobrow bp bp's bsd bstj burchfiel callout clist datakit DELIM echos hiwater init inode int IOCACK IOCNAK IOCTL ioctl Kbps lowater mazewar mesg proto PT pt ptr putp putproc queueing RS servp struct Tenex tenex thompson tl tty v7manual