Control Data Corporation 3300 Reference Manual page 29

2-8
FOR MULTIPLE {REEL}
UNIT
The MULTIPLE REEL clause must be included whenever the number of tape
units assigned, explicitly or implicitly, might be less than the number of
reels in the file. The MULTIPLE UNIT clause must be included whenever
the number of mass storage devices assigned might be less than the number
of mass storage units in the file. This can occur when the file is assigned
to disk packs. If a random file is located on multiple disk packs, all such
packs must be mounted on the drives at the time the file is opened.
RESERVE {inte g er-2} ALTERNATE
[{AREA }]
NO AREAS
The RESERVE clause allows the user to modify the number of input-output
areas allocated by the compiler. The option RESERVE integer-2 ALTERNATE
AREAS reserves integer-2 areas for the file in addition to the minimum area.
Two additional alternate areas may be assigned for unblocked files, one for
blocked files. The NO ALTERNATE AREAS option is documentary only. This
clause does not apply to random files. Blocked random files have one alternate
area; unblocked, no alternate areas. Alternate areas are never allocated to
files assigned to TTY and CRT. All integers must be positive.
{
FILE-LIMIT IS }. .
FILE-LIMITS ARE mteger-3 [THRU Integer-4]
The FILE-LIMIT clause is applicable only to permanent mass storage files
which will be internally allocated and/or expanded by the input-output con-
trol system at object time. Integer-3 indicates the number of blocks to be
initially allocated to the file. The THRU integer-4 option applies only to
sequential files.
During program execution the file limits logic operates as follows:
When an OPEN request is made on a mass storage file, the input-output
control system attempts to open the file through the MASTER operating
system. If the request to MASTER is rejected because the file does not
exist, an internal allocation is performed, using the information furnished
in the file description entry for the file. Open processing then continues
in a normal manner.
If the allocated area is exceeded and the user has speCified the THRU
integer-4 option, the
1-0
control system automatically expands the file by
ten percent of integer-3. This expansion may continue until the file reaches
the maximum limit indicated by integer-4.
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