2-2 IB! V!/370 Syste. Logic and program Deteraination--Voluae 2

Introduction To eMS The Conversational Monitor system (CMS), the major subsystem of Vft/370, provides a comprehensive set of conversational facilities to the user. Several copies of CMS may run under CP, thus providing several users
with their own time sharing system. CftS is designed specifically for
the Vft/370 virtual machine environment.
Each copy of CMS supports a single user. This means that the storage
area contains only the data pertaining to that user. Likewise, each CftS user has his own machine configuration and his own files. Debugging is simpler because the files and storage area are protected fro. other users .• Programs can be debugged fro. the terminal. The terminal is used as
a printer to examine limited a.ounts of data. After examining program data, the terminal user can enter commands on the terminal that will
alter the program. This is the most common method used to debug programs that run in CMS. CMS, operating with the VM/370 Control Program, is a time sharing system suitable for problem solving, program development, and general
work. It includes several programming language processors, file
manipulation commands, utilities, and debugging aids. Additionally, CftS provides facilities to simplify the operation of other operating systems in a virtual machine environment when controlled from a remote terminal. For example, CMS capabilities are used create and modify job streams,
and to analyze virtual Frinter output. Part of the CMS environment is related to the virtual machine environment created by CP. Each user is completely isolated from the
activities of all other users, and each machine in which CBS executes
has virtual storage available to it and managed for it. The CP commands are recognized by CBS. For example, the co •• ands allow messages to be
sent to the operator or to other users, and virtual devices to be
dynamically detached from the virtual machine configuration.
The CMS Command Language
The CMS command language offers terminal users a wide range of
functions. It supports a variety of programming languages, service
functions, file manipulation, program execution control, and general system control. For detailed information on CftS commands, refer to the CMS Figure 4 describes CMS command processing. CMS Introduction 2-3