Data Areas
The OS/VS control blocks used (CVT, DCB,
DEB, and UCB are described in Order NO.. 5Y28-0605, and in Q,§/VS2 LibrarI: Order No. GC28-0632.
The !SS co •• unicator centrol block CftSSCOft) is described in IB! Virtual !achine Facility/370 Datg Irea§ Block Logic, Order No. 5Y20-0884. Chapter 12. D!K!SS--The !SS Communicatcr 229

Diagnostic Aids
Figure 12-3 lists the .essages issued by
the DftKftSS progra.. The nearest label and
the associated .ethod of operation diagra.
are identified.
r.-----------,---------r-------------------------------------------------------------, I Label Diagra. Message Text I I I I I I RF00092 12-1 DMK8SS EIDING ERROR - MSS NOT INITIALIZED I I I I RF00149 12-2 INVALID REQUEST CODE IN V8 REQUEST I I , IRF00182 12-1 DMK8SS ENDING ERROR - teE FOR COM8. DEVICE NOT OPENED I I I IRF00190 12-1 DftK8SS ENDING ERROR - t!K!SS MUST RUN IN A VIRTUAL !ACB. I Figure 12-3. DMK!SS 8essages 230 IBM VM/370 Service Routines Prograa Logic