IBM 5280 Distributed Data System - Index of

Write-defective-sector is used for marking the sector specified by the current recordpointer as a defective sector. This instruction can only be used in a data set wherea sector is also a logical record. Write-defective-sector is specified by setting bothbits 18 and 19 to 1.For printer devjce control, bits 16 through 31 are:HexDigitsFFOOFEOOODxx19xxlAxx8Dxx99xx9AxxOptionAAAAOperationWrap test: The POR wrap test is run once each time thisinstruction is executed. Any errors encountered arereported.Line quality check: This test performs a single pollcommand without looking for a response.Read external register 13: This operation reads the contentsof register 13 into the fourth byte of the instruction(xx).Read external register 25: This operation reads thecontents of register 25 into the fourth byte of theinstruction (xx).Read external register 26: This operation reads thecontents of register 26 into the fourth byte of theinstruction (xx).Write external register 13: This operation writes thecontents of the fourth byte of this instruction (xx)into register 13.Write external register 25: This operation writes thecontents of the fourth byte of this instruction (xx)into register 25.Write external register 26: This operation writes thecontents of the fourth byte of this instruction (xx) intoregister 26.Object Cnde Instruction Format 197