You access information in the PARM field of an EXEC statement by
referring to the contents of general register 1. When control is given
to the program, general register 1 contains the address of a fullword
which, in turn, contains the address of the data area containing the
information.
The data area consists of a halfword containing the count (in binary) of the number of
information characters, followed by the information field. The information field is aligned to a
fullword boundary. Figure 1 shows how the PARM field information is
structured. Figure 1. Access to PARM field
