IBM 5280 Distributed Data System - Index of

An object code table instruction contains the system table index for the table toaccess in the second byte of the 4-byte instruction. The following illustration showshow the system table index is used to access a data table within the partition. TIledata table labeled TAB02 was the second table set up with a .TABLE controlstatement.Source:Object:R14 = TBRD{TAB02,BR60);IS2,OGWBytes 18 and 19 ofthe Partition lOB.J(\0 System Table1 t--------I231--------1'---__Data Table1 ____in Storage_System Table for Edit Format Control StringsThe system table for edit format control strings is built by the assembler when itprocesses the .FMT control statements; one system table entry is generated byeach series of .FMT control statements. The address of the system table for editformat control strings that are located within the partition is stored in the partitionlOB, at relative address 24. The address of the system table for global edit formatcontrol strings is stored in the system control block at absolute address hex EE.The system table for global edit format control strings must always be located onstorage page O.The system table for edit format control strings located within a partition consistsof one 2-byte entry for each control string. The 2-byte entry contains the address,relative to the beginning of the partition, where the control string is located. Theremay be up to 127 edit format control strings within a partition, represented bysystem table indexes 0 through 126. The last entry in the system table for editformat control strings always contains hex FFFF. If no edit formats are set upwith the .FMT control statement series in a source program, a system table for editformat control strings is built; the only 2-byte entry in the table contains FFFF.The system table for global edit format control strings consists of one 3-byte entryfor each global edit format control string. The 3-byte entry contains the storagepage number in the first byte, and the control string address (relative to the beginningof the storage page) in the second and third bytes. There may be up to 127global edit format control strings (numbered 128 to 254), represented in the systemtable with indexes 0 through 126, where index 0 represents format 128. The lastentry in the system table always contains hex FFFF.When a source program instruction refers to an edit format, it includes the formatlabel. The assembler converts the label to a format number from 0 to 127.96