34 IBM VM/370 Planning and System Generation Guide

eMS/DOS Planning Considerations for CMS/DOS Installations that use eMS/DOS must also have available a DOS/VS system
(Release 31 and above). Therefore, if you want to use CMS/DOS you must
first order and install a DOS/VS system. Also, if you want to use the DOS/VS COBOL and DOS PL/I compilers under CMS/DOS, you must order them
and install them on your DOS/VS system. DOS/VS System Generation Considerations
The CMS/DOS support in CMS uses a real DOS/VS system pack in read-only
mode. CMS/DOS provides the necessary interface and then fetches DOS/VS logical transients and system routines directly from the DOS/VS system
libraries. Also, CMS/DOS fetches the DOS/VS COBOL and DOS PL/I compilers directly from the DOS/VS system or private core image
libraries.
It is your responsibility to order the DOS/VS system and then
generate it. Also, if you plan to use DOS compilers, you must order the DOS/VS COBOL and DOS PL/I Optimizing compilers and install them on the
same DOS/VS system. When you install the compilers on
link-edit all the compiler relocatable
linkage editor control statement: ACTION REL
the DOS/VS system,
modules using the
you must
following You can place the link-edited phases in either the system or the private
core image library. When you later invoke the compilers from eMS/DOS, the library (system
or private) containing the compiler phases-must be identified for CMS. You identify all the system libraries to eMS by coding the filemode
letter that corresponds to that DOS/VS system disk on the SET DOS ON command when you invoke the CMS/DOS environment. You identify a private
library by coding ASSGN and DLBL commands that describe it. These DOS/VS system and private disks must be linked to your virtual machine
and accessed before you issue the commands to identify them for CMS. CMS/DOS has no effect on the update procedures for DOS/VS, DOS/VS COBOL, or DOS PL/I. You should follow the normal update procedure for
applying IBM-distributed coding changes to them. PTFs that must be
applied are listed in the current VM/370 Release When the DOS/VS System Must Be Online Most of what you do in the CMS/DOS environment requires that the DOS/VS system pack and/or the DOS/VS private libraries be available to eMS/DOS. In general, you need these DOS/VS volumes whenever: • You use the
compilers are
libraries. DOS/VS COBOL compiler or DOS executed from the system or PL/I compiler • private core
The
image Part 1. Planning for System Generation 35