Program Logic Manual - All about the IBM 1130 Computing System

PACKB -- Converts from unpacked binary (twoframes per word) to packed binary, withchecksumming.PCHBI -- Punches a binary paper tape record.The phase has four entry points, one correspondingto each of the functions listed above.Each subroutine is entered by an indirect BSIinstruction to the symbolic name listed above.Upon entry to each subroutine, the registersand status conditions are saved using the ENTERsubroutine in DUPCO. Another DUPCO subroutine,PHIDM, modifies the phase identificationwith the PFACE identification.Upon completion of the requested function andprior to exiting to the calling program, the originalconditions of the calling program are restoredusing the RTURN subroutine in DUPCO.GETHOThis subroutine is used by DCTL to read DUPcontrol records. The system device subroutinefor the 1134/1055 is used to read the record. An81-word buffer specified by CRBUF in CATCO isused to contain each record read. All conversionfrom PTTC/8 code to EBCDIC is performed bythe system device subroutine. When the controlrecord has been read, it is converted to packedEBCDIC within the 41-word buffer specified byPEBUF in CATCO. The subroutine then exitsto DCTL.GETBIThis subroutine reads a binary paper tape recordinto a 109-word buffer specified by THIS in CATCO.The system device subroutine for the 1134/1055 isused to read the record.Note that THIS and NEXT are reversed for eachrecord read when reading binary cards. Whenreading paper tape DCTL places the address of thebuffer having the lowest core address into THIS,since the reading of binary paper tape recordsrequires an extended buffer. The system devicesubroutine reads each frame (eight bits of data)into one word of the buffer.The word count preceding each binary paper taperecord is punched into a single frame, and is readseparately from the body of the record. After theword count is read, it is checked for validity. If it isvalid, it is used to read the record that follows.If it is not valid, the next frame is read to determineif it is a word count. In this way, deletecharacters and other special codes may appearbetween binary records or between a control recordand the first binary record.PACKBThis subroutine packs the binary record as read byGETBI into normal binary data. The packed dataoverlays the unpacked data.After packing, the checksum of the words readis verified. If the checksum is correct, the subroutinereturns to the calling program. A checksumerror causes an exit to LEAVE in DUPCO withan error parameter.PCHBIThis subroutine uses the system device subroutinefor the 1134/1055 to punch a binary paper taperecord from a 109-word buffer specified by NEXT.Buffers Used By PFACETHIS -- 109-word buffer used by GETBI for readingbinary paper tape records.The two buffers THIS and NEXT, used fordouble buffering when reading binary cards,constitute one extended buffer when readingbinary paper tape records. Double bufferingis not used for binary paper tape records.NEXT -- 109-word buffer used by PCHBI for punchingbinary paper tape records, consisting ofTHIS and NEXT taken as consecutive buffers.CRBUF 81-word input buffer used to hold a controlrecord in unpacked EBCDIC.PEBUF 41-word buffer used to hold the packedEBCDIC control record, converted from theunpacked EBCDIC in CRBUF.Section 9. Disk Utility Program (DUP) 61