Interrogating I/O Assignments
SYSIN/SYSIPT must be assigned to the device where the input source file
resides. Valid device types are reader, tape, or disk.
The user should assign the following logical units to any of the indicated device
types: SYSPCH to tape, punch, disk, or IGN
SYSLST to tape, printer, disk, or IGN SYSLOG to terminal SYSOO 1, SYS002, and SYS006 to disk. SYS003-SYS005 to tape or disk.
The maximum number of work files is six for DOS/VS COBOL Compiler (FCOBOL) and two for DOS PL/I Optimizing Compiler (DOSPLI). You must assign SYSIN/SYSIPT. If it is unassigned at compilation time, an error
message is issued and the FCOBOL or DOSPLI command is terminated.
If SYSPCH or SYSLST are unassigned at compilation time, the FCOBOL or DOSPLI EXEC file directs output to the disk where SYSIN resides if SYSIN is
assigned to a read/write eMS disk. Otherwise, output is directed to the CMS
read/write disk with the most read/write space. If SYSLOG is unassigned, it is
assigned to the terminal. If SYSOO 1 through SYSnnn are unassigned, output is
directed to the CMS disk with the most read/write space.
The current I/O assignments may be displayed on the terminal by entering the CMS/DOS LISTIO command. You can selectively display the system and/or pro­
grammer logical units as a group or as a specific unit. With the EXEC option of
the LISTIO command you can create a disk file containing the list of assignments. VSE Supervisor and I/O Macros Supported by eMS/DOS Supervisor Macros CMS/DOS supports the VSE Supervisor macros and the SAM and VSAM I/O macros to the extent necessary to execute the DOS/VS COBOL Compiler, the DOS PL/I Optimizing Compiler, and DOS/VS RPG II Compiler under CMS/DOS. CMS/DOS supports VSE Supervisor macros described in the publica­
tion VSE Macro Reference.
Since CMS is a single-user system executing in a virtual machine with virtual stor­
age, VSE operations, such as multitasking, that cannot be simulated in CMS are
ignored.
The following information deals with the type of support that CMS/DOS provides
in the simulation of VSE Supervisor and Sequential Access Method I/O macros.
For a discussion of VSAM macros, see the section "CMS Support for OS and
VSE/VSAM Functions." CMS/DOS supports physical 10CS macros and control program function macros
for VSE. Figure 44 on page 392 lists the physical IOCS macros and describes their
VSE Support Under eMS 391

Macro CCB (command control
block) IORB (Input/Output
Request Block)
EXCB (execute channel
program)
WAIT SECTV AL (sector
value) OPEN/OPENR LBRET (label processing
return) FEOV (forced end of
volume) SEOV (system end of
volume) CLOSE/CLOSER support. Figure 45 on page 392 lists the control program function macros and their
support. Refer to VM / SP System Logic and Problem Determination Guide, Volume
2 for details of the macros' operation.
Support
The CCB is generated.
Supported for DASD I/O. The REAL operand is not supported; all other operands are
supported.
Supported. Issued whenever your program requires an I/O operation (started by an EXCP macro) to be completed before
execution of program continues.
Supported for VSAM. See Figure 50 Supported. Activates a data file.
Not supported.
Not supported.
Not supported.
Supported. Deactivates a data file.
Figure 44. PhysicallOCS Macros Supported by CMS/DOS Function/ SVC. No.
Macro Dec Hex Support EXCP 0 0 Used to read from CMS or DOS/OS formatted
Disks.
FETCH 1 1 Used to bring a problem program phase into user
storage and to start execution of the phase if the
phase was found. Operand SYS= YES is not sup-
ported.
FETCH 2 2 Used to bring a $$B-transient phase into the CMS transient area (or if the phase is in the CMSDOS segment, not to load it), and start execution of the
phase if the phase was found. Operand SYS= YES is not supported. FORCE DEQUEUE 3 3 Not supported, see note 2.
Figure 45 (Part 1 of 9). SVC Support Routines and Their Operation
392 VM/SP System Programmer's Guide