Systems Reference Library - All about the IBM 1130 Computing ...

Form GA26-5918-8Page Revised 10/1/70By TNL GN26-0263..---"' -----...System --....Yes ----' -,f--- — —< Initiated Read >----... ....---......., Op......-----_ -,..- _.--'NoRead Null V02).Null Sub-sequence Request Sub-sequence Data Sub-sequence End Sub-sequenceRead Data Request(/62)i r — —j First datatransmissionIji—Channel -- TsdeactivatedIncrease ChannelTimerRead Command(/06)Read Data CommandVOA)Read CommandAcknowledge V46)Read DataAcknowledge (/6A)(Initialize LCCBProgram activates, channel to sendread end command17_Ir— — — —L .1 Second datatransmissionRead End Command(/OE)YesBusy1-No0Read EndAcknowledge V3E)Increase ChannelTimerChannel is— l deactivatedErogram Interrupt )117907A• Figure 132. 2790 Adapter Read Sequencemay be used. Read end removes the device fromdata mode and releases it for another input operation.New guidance (AS local I/0 only) or terminatingstatus is sent with read end to inform the operatorwhether the message was accepted, and hencewhether it must be repeated.If a new data buffer was assigned while initializingthe LCCB for the read end, a new readsequence is automatically initiated without an interruptto the program, provided an error is notdetected with read end acknowledge. If a new databuffer was not assigned, a channel interrupt to theprogram is generated upon receipt of read endacknowledge. Normal sequence end is indicated inthe channel sense word unless an error is detected.If an error is detected, the appropriate errorindicator is turned on in the channel senseword.2790 Adapter 249