Program Logic Manual - All about the IBM 1130 Computing System

SECTION 6. SUPERVISORFLOWCHARTSMonitor Control Record Analyzer: SUP02 - SUP05Supervisor Control Record Analyzer: SUP06-SUP08Auxiliary Supervisor: SUP10System Core Dump Program: SUP09MONITOR CONTROL RECORD ANALYZER -PHASE 1The Monitor Control Record Analyzer is the programthat decodes monitor control records and takes thespecified action.The Monitor Control Record Analyzer is enteredvia the EXIT entry point in the Skeleton Supervisor.This entry causes phase 1 of the Core Image Loaderto fetch the Monitor Control Record Analyzer andtransfer control to it.The Monitor Control Record Analyzer utilizes thesystem I/O device subroutines. Three of these subroutines(an input, an output, and the appropriateconversion subroutine) are fetched into core storageby the Monitor Control Record Analyzer itself,using SLET information provided by the SystemLoader.The Monitor Control Record Analyzer readsmonitor control records from the principal inputdevice into the Supervisor buffer, which occupieslocations @SBFR through @SBFR+79 and contains amonitor control record in unpacked, right-justifiedEBCDIC format.The principal conversion subroutine checks formonitor control records. If the principal conversionsubroutine detects a monitor control record duringthe execution of a monitor system program otherthan the Monitor Control Record Analyzer, $CTSWin COMMA is set to a positive non-zero value, themonitor control record is converted to unpacked,right-justified EBCDIC format, and the record ispassed to the Monitor Control Record Analyzer inthe locations assigned as the Supervisor buffer.If a JOB record is recognized Phase 2 is fetchedand control passed to it.Upon detecting an ASM, FOR or RPG monitorcontrol record the Monitor Control Record Analyzerfetches the first phase of the specified program usingSLET information provided by the System Loader,and transfers control to it.Upon detecting a DUP monitor control record,the Monitor Control Record Analyzer tests $NDUP,the non-DUP switch, in COMMA. If $NDUP is zero,the Monitor Control Record Analyzer fetches andtransfers control to the first phase of DUP. Otherwise,an error message is printed and the nextcontrol record is read for processing.Upon detecting a PAUS monitor control record,the Monitor Control Record Analyzer comes to aWAIT at $PRET. When the PROGRAM START keyis pressed, the Monitor Control Record Analyzerreads and processes the next control record.Upon detecting a TYP monitor control record,the Monitor Control Record Analyzer replaces theSLET information used to fetch the principal inputdevice subroutine and its associated conversionsubroutine with the SLET information for the Keyboardinput subroutine and its associated conversionsubroutine. These subroutines are then fetched andused for the reading and converting of subsequentinput records from the Keyboard.Upon detecting a TEND monitor control record,the Monitor Control Record Analyzer replaces theSLET information used to fetch the principal inputdevice (the Keyboard) subroutine and its associatedconversion subroutine with the SLET informationfor the device subroutine and conversion subroutineused with the device normally assigned as theprincipal input device, i. e. , not the Keyboard.These subroutines are then fetched and used for thereading and converting of subsequent input records.Upon detecting a CPRNT monitor control record,the Monitor Control Record Analyzer replaces theSLET information used to fetch the principal printdevice subroutine with the SLET information for theConsole Printer output subroutine. (This replacementis permanent and can be changed only bySystem Loader with a reload function.) This subroutineis then fetched and used for the printingof subsequent output records on the ConsolePrinter.Upon detecting an EJECT monitor control record,the Monitor Control Record Analyzer ejects the pageon the principal print device, prints the currentpage heading, and reads and processes the nextmonitor control record.Upon detecting an XEG monitor control record,the Monitor Control Record Analyzer tests $NXEQ,the non-execute switch, in COMMA. If $NXEQ iszero, the Monitor Control Record Analyzer fetchesand transfers control to PHASE 4 (see below).Otherwise, the Monitor Control Record Analyzerprints an error message and reads the next controlSection 6. Supervisor 19