Atari 400 Technical Reference Manual page 70

LOCK
This command allows you to prevent write access to any
number of named files. Locked files can not be deleted, renamed,
nor opened for output unless they are first unlocked. Locking a
file that is already locked is a valid operation. The Handler
expects a device/filename specification; then all occurrences of
the filename specified will be locked, using the wild-card rules.
You set up these following IOCB parameters prior to
calling CIa:
COMMAND BYTE
=
$23
BUFFER ADDRESS
=
pointer to device/filename specification.
After a LOCK operation, the following IOCB parameter will have
been alter.d:
STATUS
=
result of LOCK operation; see Appendix B for a list
of possible status codes.
UNLOCK
This command allows you to remove the lock status of any
number of named files. Unlocking a file that is not locked is a
valid operation. The Handler expects a device/filename
specification; then all occurrences of the filename specified
will be unlocked, using the wild-card rules.
You set up these following IOCB paramete~s prior to
calling CIO:
COMMAND BYTE
=
$24
BUFFER ADDRESS
=
pointer to device/filename specification.
After an UNLOCK operation. the following IOCB parameter will have been
altered:
STATUS
=
result of UNLOCK operation; see Appendix B for a
list of possible status codes.
DELETE
This command allows you to delete any number of unlocked
named files from the directory of the selected diskette and to
deallocate the diskette space used by the files involved. The
Handler expects a device/filename specification; then all
occurences of the filename specified will be deleted, using the
wild-card rules.
OPERATING SYSTEM C016555 -- Section 5
85