Planning Considerations for CMS Additionally, you can invoke the CP commands available to all virtual
machines under VM/370 directly from CMS. Using these CP commands, you
can send messages to the operator or to other users, dynamically change
your virtual machine's configuration, and invoke spooling facilities.
In CMS, the facilities of CP and CMS together appear as those of a
single integrated system.
To use CMS, you must first gain access to a virtual machine via the CP LOGON command, and IPL CMS. Then you can enter commands or data from
the remote terminal (virtual operator's console). Each command, upon
completion, returns control to you. For information about how to use CMS and for a description of all CMS commands, see the ang and the VM/37Q. eMS Program language Facilities The languages available under CMS include: S/370 Assembler VS BASIC PL/T as FORTRAN IV OS/VS COBOL DOS PL/I Optimizer DOS/VS COBOL VS APL The assembler is distributed with VM/370. The language compilers
that are program products must be ordered separately. For a complete
list of language processors that can be executed under CMS, see
"Appendix A: Program Products, Installed User Programs, Field Developed
Programs and Emulators." CMS executes the
provided to invoke
of CMS. compilers via interface modules. CMS commands are
the compilers within the conversational environment OS/VS COBOL programs, using the following facilities, can be compiled
under CMS, but must be transferred to a machine (virtual or real)
running as for execution. QSAM & BDAM spanned records ISAM RERUN statement
label-handling options OPEN REV ERSED Sort feature
Segmentation feature ASCII code feature
Forced end of volume TCAM feature
as PL/I programs, using the following
under CMS, but must be transferred to a
running 05 for execution. Mul ti tas king
Teleprocessing file support ISAM Backwards attribute
facilities, can be compiled
machine (virtual or real) Part 1. Planning for System Generation 23

Planning Considerations for CKS Spanned records for buffered files . Sort-merge
Checkpoint-restart ASCII data sets
Track overflow
The DOS/VS COBOL and DOS PL/I Optimizing compilers execute in the CMS/DOS environment of CKS. The CKS/DOS environment does not support
the execution of DOS programs that use: • sort exits. The DOS/VS COBOL and DOS PL/I Optimizer SORT verbs are
not supported in CKS/DOS. • Teleprocessing, indexed sequential access method (ISAK), or direct
access method (DAM). CMS/DOS supports only the sequential access
method (SAK, and virtual storage access method (VSAK). • Kultitasking. CKS/DOS background partition. CMS TEXT PROCESSING FACILITY supports only a single partition, the
Text processing facilities that can create formatted output from one or
more CKS files containing text and/or control words are available
through the SCRIPT command. SCRIPT/370 is an IBM Installed User Program that must be ordered separately.
Limited Support of OS and DOS in eMS Object programs (TEXT files) produced under CMS and under OS in real or
in virtual machines can be executed under CKS if they do not utilize
certain OS functions not simulated by CKS. Object programs using
nonsimulated OS macro functions must be transferred to an appropriate
real or virtual OS machine for execution.
Sequential and partitioned data sets residing on as disks can be read
by OS programs running under CMS. Also, certain CMS commands can be used
. to process data sets on as disks. CMS simulates the control blocks, supervisor and I/O macros, linkage
editor and fetch routines necessary to compile, test, and execute DOS/VS programs under CMS. The support for the DOS user is comparable to that
for the OS user. CMS supports VSAM and access method services for DOS and OS users. CMS supports VSAM for the following." compilers: OS/VS COBOL, OS PL/I, VS BASIC, DOS/VS COBOL, and DOS PL/I. CMS does not support VSAM for
assembler language programs or VS APL. The application programmer who normally uses CMS to interactively
create, modify, and test his programs may require facilities not
supported in CMS (for example, an OS program using ISAM). He can
alternately execute CKS and another operating system in the same virtual
machine. A description of the actual processes for reading as or DOS files is
in the !11Ll1Q A description of alternating operating
systems is in !1!L37Q in 24 IBM VM/370 Planning and System Generation Guide