Program Logic Manual - All about the IBM 1130 Computing System

Likewise, information acquired by Phase 1 thatmust be passed on to Phase 2 and error messages requiredby both phases reside in a low core positionso as not to be overlayed by Phase 2.PHASE 2At the conclusion of either an initial load or reload,the SLET and Reload Tables are checksummedand the result stored in the last word of the ReloadTable sector.Phase 2 displays appropriate error messages, asI necessary, using the WRTYZ subroutine in corestorage.FUNCTIONS, INITIAL LOAD AND RELOADPhase 2 checks the phase ID number sequence forascending order and completeness throughout aninitial load, and during the addition of one or moreprograms during a reload. At other times duringa reload, the phases present should be in ascendingorder, but omissions are allowed.Phase 2 performs a checksum test on all type A(data) records.Phase '2 builds the Reload Table in core storageas the monitor system program phases are loaded.Each 3-word entry in the table consists of the IDnumber of a phase requesting SLET data, the relativelocation within the requesting phase where theSLET data is to be stored, and the number of SLETitems to be supplied by the System Loader. On aninitial load, this Reload Table is written to disk insector nRTBL.If so indicated in columns 12 through 15 of theLoad Mode control record, phase 2 bypasses theprograms described by phase ID pairs 2, 3, 8 and/or 9 from the PHID control record(s).Phase 2 updates the version and modification levelnumbers in the parameter #SYSC in sector ( 9.,D DCOMof the cartridge. These numbers are taken directlyI from the first PHID control record. No comparisonwith previous version and modification level numbersis made.Phase 2 determines from the data obtained fromthe System Configuration records which devices arethe principal I/0 and principal print devices. Phase2 builds five special sets of SLET entries for thespecified devices as well as for the principal I/0 andprint device conversion subroutines.Phase 2 steps through the Reload Table andsearches out every phase requesting SLET data.It then searches out the SLET data that is requested,places it in the requesting phase, and writes thatphase back to disk. This continues until the end ofthe Reload Table (/F FEE) is reached.Phase 2 substitutes zeros for the SLET data requestedby a phase if that phase requested a programdescribed by phase ID pair 2, 3, 8 or 9 and thatprogram is not present on the cartridge. For examp:le,the Assembler Program (represented by phase ID pair3) may have been deleted or never loaded.FUNCTIONS, INITIAL LOAD ONLYPhase 1 has cleared to zero the sectors that willbecome the SLET table. The SLET entries arefilled in as each monitor system program is stored.Phase 2 checks for missing phases. All phasesspecified in the PHID control record must be present,except when one or more programs are bypassed.Phase 2 keeps a record of the highest sector loadedso that the sector addresses for the Supervisor ControlRecord Area (SCRA), Core Image Buffer (CIB), LocationEquivalence Table (LET), and User Area (UA) ondisk may be correctly established.Phase 2 checks the data obtained from the I,oadMode control record, and if a program is bypassed,no gap is left in SLET. The next program loadedfollows immediately on the cartridge and the SLETentry for its first phase fills the first availablelocation in SLET.FUNCTIONS, RELOAD ONLYPhase 2 verifies that the file-protection address isnot greater than /062F. (Otherwise, phase 2 cannotbe temporarily stored on disk.)Each time a phase with a positive phase ID numberis reloaded, the Reload Table is searched. If thatphase ID is present, it is removed and the tablerepacked.Phase 2 updates the SLET entries for each phaseas that phase is reloaded.Phase 2 provides for expansion of the system intothe Cushion Area when required. If a phase growsby more than one sector, it is expanded accordingly.All subsequent SLET entries are updated each timean expansion occurs. A check is made to see thatthe Supervisor Control Record Area (SCRA) is notoverlayed.The phase ID range of an existing program may beexpanded at the 'upper end' to permit addition of oneor more phases to that program. In such a case,the phase whose ID is one less than the first phase tobe added must be present so that a pointer can locatethe position in SLET where data for the added phasewill be inserted. SLET entries above the addedphase will be shifted to provide 4 SLET words for10