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Task Show and Tell file    TC100000


A. Overview

Function: The Show and Tell file is used to pass parameters to tasks
which are already running and which can make some use of parameters
during execution.

Details: The use of this file is for interactive, but asynchronous,
control of tasks.  Thus, the only program to write new parameters
into the file is AIPS.  Those tasks which can change parameters during
execution (e.g. number of iterations) or which can sensibly be told
to quit early may read the file at any time.  If information intended
for them is present, then the task should fetch that data and remove
the indication of the communication to it.

Name: The file is named TC100000.  It is a permanent file and must
contain at least (4 + 8 * NINTRN) 256-word records.  It is
created during system installation.


B. File structure

The file consists of 4 directory records followed by up to 120
data records.  The directory records contain 64-word logical
records one for each value of NPOPS, 4 per physical record.
Each 64-word record contain 8 8-word logical records, allowing
up to 8 TELL operations to be queued for each POPS number at any
one time.  The structure of these 8-word records is

    WORD    TYPE             DESCRIPTION

     1     I*4(2)      Task name (Hollerith)
     3     I*4(2)      Time (YY/MM/DD, HH/MM/SS)
     5     I*4         User number
     6     I*4         Operation
     7     I*4(2)      Reserved

The data records follow, one for each operation, 8 for each POPS
number.  They are adverb values specified in the Inputs section
of the HELP file, preceded by the value of the adverb OPTELL.
