Sequential devices

CICS® uses BSAM to control sequential devices such as card readers, line printers, magnetic tape units, and DASD to simulate terminals. Only unblocked data sets can be used with BSAM.

These “sequential terminals” may be used before actual terminals are available, or during testing of new applications.

To define a sequential device, code the following macro instructions:
       DFHTCT TYPE=INITIAL,
              ACCMETH=(NONVTAM)    defining the access
                                   method
(Define the following macro instructions contiguously.)
  DFHTCT TYPE=SDSCI,
         DSCNAME=isadscn,     defining the input
         DDNAME=indd, ...      data set
  DFHTCT TYPE=SDSCI,
         DSCNAME=osadscn,     defining the output
         DDNAME=outdd, ...     data set
  DFHTCT TYPE=LINE,
         ISADSCN=isadscn,
         OSADSCN=osadscn, ...
  DFHTCT TYPE=TERMINAL,
         TRMIDNT=name, ...

The two data sets defined by the DFHTCT TYPE=SDSCI macros simulate a CICS terminal known by the name specified in the TRMIDNT operand of the DFHTCT TYPE=TERMINAL macro. The DSCNAMEs of the input and output data sets must be specified in the ISADSCN and OSADSCN operands of the DFHTCT TYPE=LINE macro respectively.

The end of data indicator (EODI) for sequential devices may be altered using the EODI system initialization parameter.