DKKIOSHA point for halting a device. If device is not active, return to
caller. If IOBLOK active, reset the IOBLOR to halt the device and
mark the device reset in RDEVBLOK. DKKIOS, IOS10KI path is busy with a burst mode operation, stack the IOBLOK to halt the operation when the channel path becomes available.
Return to caller. DI1KIOSIN from I/O new PSi. Check old PSi. If problem mode, save
processor status in the VMBLOK. DMKSCNRN Locate RCHBLOK, RCUBLOK, and RDEVBLOKs for interruption unit. DMKVIOIN ---Process dedicated channel interruption condition. If control unit
end or channel available interruption occurs, restart the operation,
if interruption does not occur stack it. DMKIOSIN IOBLOK is not active on RDEVBLOK interruption. call DftKIOS. IOSENSE Schedule sense operation, then go to dispatcher. DMKIOS, For PCI or CE interruptions, copy and stack the IOBLOK. Process PCI or CE interruptions, if related to local graphic device
or nondedicated TP line. DMKIOS, DOSERSE For split seek complete interrupt, rechain the seek and reschedule
operations. DMKSTKIO -- Stack IOBLOK and restart any units freed by the interruptions. DMKDSPCH, DMKDSPA ---rj-the syste.-Iock is held or is available. exit to the main entry of
the dispatcher, DMKDSPCH. Otherwise, exit to DftKDSPA to try to
redispatch RURUSER. TERMINAL CONSOLE I/O CONTROL, START/STOP, 3210, 3215, AND OTHERS DMKCRSEN ---Per-unstacked CPEXBLOK, on enable or disable function, check current
status of the current real device and set flag in RDEVFLAG. Build CONTASK and IOBLOK. Issue SIO for enabling or disabling function and check return. DP.lKDSPCH dispatcher.
1-196 IBP.l VM/310 System Logic and Problem Determination--Volume 1

DMKCNSIC -- Entry from DMKQCN module. Build I/O CCi string as defined by the
console device type. Also select the proper line code to interface
with the device. Place in CONTASK. For output CONTASK determine the
correct translation table applicable to terminal communications (DMKTBL). To append proper control character to the data stream for
the particular device type, refer to the following labels: • !NCiT!! Te1etypewri ters • DMKCNS, INC2741 2741;-3761--- • DMKCNS, INC1050 1050;-1051 --- • INC321Q. 3210, 3215 Attempt to start I/O by halting the current operation, if the
operation is a "prepare" CCW or the input is a read and the
forthcoming output is a priority write CONTASK. DMKFREE ---aet-storage to build IOBLOK, if needed. Rl1KCNS!! Set return address in IOBIRA. Start I/O. If busy condition encountered build CPEXBLOK and queue for
1a ter exec uti on. DMKDSPCH dispatcher. C!BREAK For an actIve-input task halted, RDEVFLAG=RDEVHIO to process priority output task. DMKFREE ---SuIId CONTASK for reverse break CCWs. Move the input CONTASK following the last priority write output CONTASK on the chain. For unit check with intervention required, assume an attention
interruption and build a "prepare" CCi for the 2741 • CN SL Q5iI For unit check and timeout condition -logoff the virtual machine and
re- enable the line. DMKCNS, CNSRTRY ---Per dati-check and other conditions, retry the previous operation. Process co.pleted output CONT1SK. DMKCNSIN ---rnterpret interruption status and CCW residual count for input CONTASK completion. CNI!£! Validate input data and control characters and translate to EBCDIC froll line code. DMKTRMID to identify, if applicable, the line code identification;
PTTC/EBCD or correspondence.
CP Method of Operation and Program Organization 1-197