Program Organization
This section describes the program organization of the DMKMSS module. DMKMSS The MSS communicator program. Point tMKMSS Usage BO-R9: Work registers R10: Workarea base
R11: Program base B12: Work register
B13: legister savearea base R14-R15: Work registers
Chapter 12. MSS Communicator 227

Directory
Figure 12-2 is an alphabetical list of the
major labels in the DMK8SS program. The
figure indicates the associated method of
operation diagrams and it provides a brief
description of the operaticn performed at
the point in the program associated with
each label. I I ILabel Diagram Description I DIAG
L1
L2 8AINLOOP 8SSCHECK PROLOG RF00082 RF00092 RF00122 RF00149 RF00182 RF00190 12-2
12-1
12-2
12-2
12-2
12-1
12-1
12-1
12-2
12-2
12-1
12-1
Issues DIAGNOSE code X '78' subfunction X'08' or X'OC'. Follows pointers through the tCB, DEB, and UCE to find
the communicator device address. Determines the type of 855 request (mount or de.cunt).
Issues DIAGNOSE code X'78' subfunction X'04', requesting wcrk.
Sets the 8SC completion code for V8/370. Initializes for DIAGNOSE code X'78' subfuncticn X'OO'. Issues STIDP instruction to ensure running in a virtual
machine.
Issues message that ftSS is not initialized. Waits for the communicator device attention interruption.
Issues message for invalid request code in V8 request.
Issues message that DeE is not opened.
Issues message that this must run in a virtual machine. Figure 12-2. D8K8SS Label Directory
228 IBM V8/370 Service Routines Program Logic