VM/370 RSCS .. SML , in ... I HOST Mode
RJE Mode
VM/370 RSCS SML in .if RJE Mode I( .... Jobs
PRINT and PUNCH Output
Jobs ..
PRINT and PUNCH Output II.. ) ... A ) ... Remote
Work Station Remote
Batch System Figure 5. Data Flow between Rses and Remote Stations via the set Line
Driver SML PROCESSORS To support the HOST and RJE processing aodes, the SML program provides
seven "processors," or routines, that handle the seven functions
required to support the two processing modes. Figure 6 is a list of the SML processors, the processing modes they support, and a brief statement
of their function. When a command is transmitted from a reaote station to RSCS, receives the command and coordinates processing of the command
supervisor routines and the REX task command module DMTCMX. SI!L with
The SML Frocessor, $WRTN1, processes a command request from a reaote
station by Fassing a command request element to the REX task (module DMTCMX) via a GIVE request. DMTCMX then determines whether the co.mand
should be executed by DaTCeX, DMTAXS, or bi the line driver. If tbe
command is to be executed by the line driver, it is passed back to SlL via an ALERT request. The SML routine CMIPROC then executes the
command. RSCS Introduction 3-15
r I Processor Mode Function $CRTNl HOST/RJE $PRTN1 RJE $URTNl RJE $JRTNl HOST $WRTNl HOST/RJE $RRTNl HOST/RJE Processes the following MULTI-LEAVING control
records: permission to transmit, request to
transmit, and SIGNON control records. Precesses print file records received from remote stations and passes them to the spool system.
Processes punch file records received fro.
remote stations and passes them to the VM/370 spool system.
Proc,esses job file records received froll the
remote station and passes them to the VM/370 spool system.
In HOST mode, passes command request elements,
via to DMTCMX for processing.
In RJE mode, passes message request elements
to the RSCS operator's console.
Receives records from the VM/370 spool system
for transmission to remote stations. CMDPROC Executes local commands passed by DMTCMI, and
passes messages and commands to remote pta tions.
Figure 6. SML Function Processors
THE SML LINE I/O HANDLER ROUTINE: COMSUP The SML line I/O handler routine, COMSUP, controls communications on tbe ESC line fer SML. This routine receives data from the BSC line and
passes the da t.a to the deblocker routine ($TPG'ET). COMSUP also sends
data (which has been blocked by the blocker routine, $TPPUT) to a remote
station. COMSUP is also responsible for acknowledging receipt of data
over the line using the standard BSC line control characters.
The $START routine is entered when SML is required (by either a remote station or a virtual machine) to perform a function. The purpose of this routine is to select a function to execute. The routine performs
this function by using a commutator table, a list of synch locks, and
task control tables.
The SML commutator table is a branch table consisting of branch (E)
and no-operation (NOP) instructions. The targets of the branch instructions are the seven processor routines, each of which performs a
specific function. When the service of a processor is not required, tbe
commutator Table entry for that processor is a NOP instruction. When the function of the processor is required, the NOP instruction in tbe
commutator table entry for that processor is replaced with a B
instruction, thereby opening a gate in the commutator table.
3-16 IBM VM/370: System Logic and Problem Determination--Volume 3
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