[Simh] IBSYS end of file question

[kenr]

Hi,
I'm new to simh and have a problem I'm hoping someone may help with.

Could someone tell me the purpose of the assert pc =7465 and det mta4 in 
the job stream?

I am using i7094 simulator to compile and run a fortran II and fap 
program.  I run the ibsys.txt script and see no errors but the simulator 
hangs following a HALT instruction after the programs are compiled and 
executed.

I assume this HALT is a result of the $STOP command?

The system hangs after the HALT and does not respond to ctl-C or ctl=D 
or anything else.  However, if I start another terminal and run some 
other test it sometimes awakens the terminal and simh continues.  I see 
this problem with example  tests from sky-vision.com also.

What could cause this to hang?

1.    Here is the tail end of the input job stream;  When the program 
executes it simply prints the data following the *   DATA card.  The 
program does seem to be running as I expect.  I've eliminated some blank 
lines to condense this a little.

             OCT     7777
              OCT     77777
  MSTBL PZE
             END
*          DATA
           START OF COMPILER
        JAT     ID SCAN
        FIN
~
$EOF
$IBSYS
$STOP

2.   Here is the tail end of the system output on sysou1.bcd showing the 
text output from execution;

         EXECUTION
           START OF COMPILER
        JAT     ID SCAN
        FIN
  EOF
  IBSYS
  STOP
         1792 LINES OUTPUT THIS JOB.
       FORTRAN MONITOR RETURNING TO IBSYS
$STOP
  PERIPHERAL UNIT POSITIONS AT END OF JOBS
  SYSPP1  IS   A8    REC. 00000, FILE 00001
  SYSOU1  IS   A4    REC. 00574, FILE 00000
  SYSIN1  IS   A3    REC. 00002, FILE 00001
END OF JOBS
HALT instruction, PC: 07465 (SXA 7510,4)


3.   And here is the tail end of the LO from sysou1.bcd
       EXECUTION
        1792 LINES OUTPUT THIS JOB.
      FORTRAN MONITOR RETURNING TO IBSYS
            $STOP
             PERIPHERAL UNIT POSITIONS AT END OF JOBS
             SYSPP1  IS   A8    REC. 00000, FILE 00001
             SYSOU1  IS   A4    REC. 00574, FILE 00000
             SYSIN1  IS   A3    REC. 00002, FILE 00001
            END OF JOBS
EOF  END OF OUTPUT


4.    and, finally here is the do_ibsys.txt file used to create the 
input stream;

; command file to run ibsys from within simh
; argument 1 = job file
; argument 2 = print file
;
! rm punch.* print.* sysou1.* sys*.bin
! /Users/admin/development/simh/ibsys_kit/gendate > date.txt
! cat date.txt %1 /Users/admin/development/simh/ibsys_kit/eof.dat 
/Users/admin/development/simh/ibsys_kit/ibsys.ctl > sysin.txt
! /Users/admin/development/simh/ibsys_kit/txt2bcda sysin 84
set cpu 7094
att -er cdr /Users/admin/development/simh/ibsys_kit/ibsys.ctl
att cdp punch.txt
;att lpt print.txt
att -ef mta1 p7b /Users/admin/development/simh/ibsys_kit/asys1.bin
att -ef mta2 p7b /Users/admin/development/simh/ibsys_kit/asys8.bin
att -f mta3 p7b sysin.bcd
att -f mta4 p7b sysou1.bcd
att mta5 /Users/admin/development/simh/ibsys_kitsysut1.bin
att mta6 /Users/admin/development/simh/ibsys_kit/sysut3.bin
att mta7 /Users/admin/development/simh/ibsys_kit/sysut2.bin
att mta8 /Users/admin/development/simh/ibsys_kit/syspp1.bin
att mta9 /Users/admin/development/simh/ibsys_kit/sysut4.bin
att mta10 /Users/admin/development/simh/ibsys_kit/sysck2.bin
dep ss1 0
boot mta1
run 3
assert pc =7465
det mta4
! /Users/admin/development/simh/ibsys_kit/bcd2txta -p sysou1.bcd %2
det all
;! rm reader.* sys*.bin
;! rm sysou1*.bcd sysin.*