Managing tape drives

ALLOC	Allocate a device
DEALLOC	Deallocate a device
MOUNT	Mount a device
DISMOUNT	Dismount a device

Similar problems with processes occur when allocating and mounting tape drives. The DCL command `ALLOCATE' will allocate the device to the DCL subprocess. This may be what you want; for example, if you are going to use another DCL command (such as `BACKUP') to read or write the tape. However, if a tape is to be processed using a FIGARO command, say, it must be allocated to the process running ICL. A set of commands has been provided for this purpose.

ALLOC allocates a device and may specify a generic name; the name of the device actually allocated will be returned in the optional second parameter. For example:

    ICL> ALLOC MT
    _MTA0: Allocated
    ICL> ALLOC MT (DEVICE)
    _MTA1: Allocated
    ICL> =DEVICE
    _MTA1:

DEALLOC deallocates a device.

MOUNT performs a MOUNT/FOREIGN at the tape's initialised density. It does not provide the many qualifiers of the DCL command. There are several additional optional parameters for some of these commands.

DISMOUNT has an optional parameter which is used to specify that the tape be dismounted without unloading:

    ICL> DISMOU MTA1 NOUNLOAD