180 IBM VM/370 eMS User's Guide

Pg. of GC20-1819-2 Rev March 30, 1979 by Supp. SD23-9024-1 for 5748-XX8 Section 10. Using Access Method Services
and VSAM under CMS and CMS/DOS This section describes how you can use CMS to create and manipulate VSAM catalogs, data spaces, and files on OS and DOS disks using access method
services. The CMS support is based on DOS/VSE and VSEjVSAM; this means
that if you are an OS VSAM user and plan to use CMS to manipulate VSAM files you are restricted to those functions of access method services
that are available under the access method services portion of VSEjVSAM. The control statements you can use are descrited in the publication You can use CMS to: • Execute the access method services utility programs for VSAM and SAM data sets on OS and DOS disks and minidisks. CMS can both read and
write VSAM files using access method services. • Compile and execute programs that read and write VSAM files from DOS programs written in the COBOL or PLjI programming languages. • Compile and execute programs that read and write VSAM files from CS programs written in the VS BASIC, COBOL, or PLjI programming
languages. • Assemble assembler language source programs under CMS that use VSAM macros. You must create your own macro library from OS or DOS macro
libraries. VSAM files written under eMS are wholly compatible for reading and
writing under OS and DOS systems. None of the CMS commands normally used
to manipulate CMS files are applicable to VSAM files, however. This
includes such commands as PRINT, TYPE, EDIT, COPYFILE, and so on. This section provides information on using the CMS AMSERV command
with which you can execute access method services. The discussion is
divided as follows: • nOsing the AMSERV command" contains general information. • "Manipulating OS and DOS Disks for Use With AMSERV" describes how to
use CMS commands with OS and DOS disks. • "Defining DOS Input and Output Files" is for eMS/DOS users only. • "Defining OS Input and output Files" is for OS users only. • "Using AMSERV Under CMS" includes notes and examples showing how to
perform various access method services functicns in CMS. EXECUTING VSAM PROGRAMS UNDER CMS The commands that are used to define input and output data sets for
access method services (DLBL) and for CMS/DOS users (ASSGN) are also
used to identify VSAM input and output files for program execution.
Information on executing programs under CMS that manipulate VSAM files
is contained in the program product documentation for the language
processors. These publications are listed in the Section 10. Using Access Method Services and VSAM 181