v7 man page for lock

LOCK(2) 							System Calls Manual							   LOCK(2)

NAME
       lock - lock a process in primary memory

SYNOPSIS
       lock(flag)

DESCRIPTION
       If the flag argument is non-zero, the process executing this call will not be swapped except if it is required to grow.	If the argument is
       zero, the process is unlocked.  This call may only be executed by the super-user.

BUGS
       Locked processes interfere with the compaction of primary memory and can cause deadlock.  This system call is not  considered  a  permanent
       part of the system.

ASSEMBLER
       (lock = 53.)
       sys lock; flag

								       local								   LOCK(2)