IAS V2.0 AND V3.0 TCS "SPAWN" ROUTINE"

                                                                            






        The file TSPAWN.MAC contains:



             1.  A fortran callable subroutine, "TSPAWN",  which  takes  the

                 exact syntax of the fortran "spawn" directive call and uses

                 the arguments to run the task via timesharing control  ser-

                 vices (TCS) rather than as a real-time task.



             2.  A macro definition for a "SPWN$T" macro which takes the ex-

                 act  syntax  of  the  macro "SPWN$S" directive and uses the

                 stack to pass arguments to the TSPAWN routine.





        The file MCRISH.FTN contains a primitive example of how  the  TSPAWN

        routine  can  be used to execute MCR command lines which are entered

        from a terminal.  This program is merely for example sake as it does

        not  handle  error  conditions  adequately.  it could never be a re-

        placement for MCR or MCR mode!!



        The source has a commented-out label, "SPAWN::" which would cause it

        to  be  a transparent replacement module in the taskbuild of fortran

        programs which already use the "SPAWN" call.  It does not do so  for

        macro  programs since they EMT 377 directly, whereas fortran calls a

        routine named "SPAWN".  



        When using this subroutine, some considerations must be  taken  into

        effect:



             1.  It only works on an IAS system which has  full-timesharing.



             2.  The function contained here is a SUBROUTINE which ultimate-

                 ly  does  its  job by issuing QIO's to device PI.  The real

                 SPAWN ultimately issues an executive directive via  an  EMT

                 377.  



             3.  Therefore, the task must have the appropriate TP1  and  TP2

                 masks to issue TCS calls.



             4.  The CLI for the terminal must have  been  allocated  enough

                 job  nodes  to  run the number of tasks required.  For PDS,

                 this can be done by editting the PDS build command file and

                 following  the instructions to automatically allocate extra

                 job nodes.  This can also be accomplished by  specifying  a

                 MAX paramater in an ALLOCATE/TERMINAL command line.



             5.  Under PDS, it is also essential that the MTS value for  the

                 user is greater than 2.



             6.  Because TCS is used, there are additional facilities avail-

                 able.    There   are  also  some  ignored  arguments.   See

                 TSPAWN.MAC for full details.






        IAS V2.0 AND V3.0 TCS "SPAWN" ROUTINE"                        PAGE 2

                                                                            






        A full description of the routine's functions  and  calling  methods

        are  included in the "TSPAWN.MAC" file itself.  The routine requires

        about 2000 (octal) words.  Please read the comments  in  the  source

        file.



        To use, assemble the source (MAC TSPAWN) and link  the  object  file

        with  the  main program object.  To use the example program, compile

        MCRISH.FTN, then LINK MCRISH,TSPAWN.   Then  RUN  MCRISH.   It  will

        prompt MCR>.



        Unfortunately, there are still some problems with the  routine.   It

        seems  that  when  the  auto-install function is used under IAS V2.0

        that INS becomes confused as to the default device and UIC.  The au-

        thor  has not had enough time to test all the promised functionality

        of the routine, but is willing to aid in debugging any  problems  if

        it is used and would like to know of any corrections made.  



        Any questions or comments may be directed to:

             Bob Freepartner

             Host International, Inc.

             P.O.  Box 1760

             Santa Monica, Ca.  90406

             (213)450-7566