IBM 5280 Distributed Data System - Index of

Read a Record from a Data Set (READ)RnBRnSource: READ +, [~}0~Object: 2000 fJ II II0 Bits:891011o = Sequential record access method1 = Relative record or key access methods0= Overlap mode (0 specified)1 = Nonoverlap mode (N specified)Not used, always zeroNot used, always zerofJ Data set number: The number (hex 1-F) of the data set to be read.II Format number: The number (hex 01-FE) of the format to use. If no formatnumber is specified, this is hex FF. For a data directed read, this is hex00.II Record to read: The current record number in the lOB is set to the recordnumber that is to be read. The location of the record to be read can be:• Rn for the address of the decimal register that contains the key to therecord .• BRn for the address of the binary register that contains the relative recordnumber of the record.• Hex 07 (- specified) for reading the previous record.• Hex 08 (0 specified) for reading the current record.• Hex 09 (+ specified) for reading the next record.The current record number in the lOB is set to the record number that is to beread. The specified record is read from diskette and put into the logical I/O buffer.If formatting (fmt) is specified, data is formatted, moved from the logical I/Obuffer, and put into the storage indicated by the format.Object Code Instruction Format 169