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•CICS is divided into a set of service programs responsible
for different aspects of transaction execution.
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•CICS runs under the direction of the management services
program. The most important of these
is the Task Control Program ( KCP).
The KCP looks through the Active Chain of executing tasks and
determines the highest priority work.
If there is no work, the KCP puts CICS into an operating system wait
state. [Hudders]
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•Data Management Services are handled by the File Control
Program (FCP) for VSAM datasets, DL/I for IM databases, and SQL for DB2
access. [Hudders]
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•The Application Programming Interface ensures that CICS
services are invoked in a consistent manner.
The Program Control Program (PCP) handles the program selection and
execution using the Program Processing Table (PPT). Requests from the application program are
sent to the correct resource. [Hudders]
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•Basic Mapping Support (BMS) handles the defined screen
formats, called mapsets. The are two
types of mapsets. Physical mapsets
determine the location, appearance, and operation of display data. Symbolic mapsets allow manipulation of the
screen data.[Menendez]
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•The Terminal Control Program (TCP) controls messages from
terminal sessions into CICS and CICS responses back to the terminal
session.[Hudders]
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