IBM 5110 User Manual page 58

The following formula shows how much storage in the active
workspace is required to perform an input or output operation to tape
or diskette using an APL shared variable (see Input/Output Contro/):
REQUIRED STORAGE
=
BUFFER
+
SHARED VARIABLE +
OVERHEAD
where:
• REQUIRED STORAGE is the amount of storage that must be
available in the active workspace (see OWA) before an input or
output operation to tape or diskette can be performed. If there is
not enough available storage, a WS FULL error occurs.
• BUFFER is the amount of storage required by the data assigned to
the shared variable. This storage is only used during the
input/ output operation.
• SHARED VARIABLE is the amount of storage required for the data
assigned to the shared variable.
• OVERHEAD is the amount of storage used when the input/output
operation is specified. The overhead is as follows:
OUT and OUTF operations-812 bytes
IN operation-792 bytes
INR, lOR, IORH operations-356 bytes
Active Workspace Control 53