Defining the DPSS

DPSS maintains communication between the application program and PSF. DPSS, in turn, uses the functional subsystem interface (FSI) to communicate with PSF and to deliver data to the printer.

To use direct-printing mode, you must first define DPSS as a z/OS® subsystem by modifying the PARMLIB member IEFSSN00 or by defining a new IEFSSNxx member. IEFSSN00 (or the newly created member) must contain the following statement:

SUBSYS SUBNAME(DPSS) INITRTN(APSADPSS) INITPARM(n)

where

• DPSS is the subsystem name.
• APSADPSS is the program name.
• n is the maximum number of FSAs (printers) to be used per address space.

PSF supports a maximum of 128 FSAs. The actual number of FSAs depends on several factors, such as the number and size of resources used in the print jobs and the amount of virtual storage available.

Figure 49 shows a job stream that can create a new IEFSSNxx member of SYS1.PARMLIB. Note that if you create a new IEFSSNxx member, you must update the IEASYSxx member to point to IEFSSNxx, and an IPL is required.

 //IEFSSN JOB ...,MSGLEVEL=1,MSGCLASS=A,CLASS=A
 //STEP1 EXEC PGM=IEBUPDTE,PARM=NEW,REGION=256K
 //SYSPRINT DD SYSOUT=A
 //SYSUT1 DD DSN=SYS1.PARMLIB,DISP=SHR
 //SYSUT2 DD DSN=SYS1.PARMLIB,DISP=SHR
 //SYSIN  DD  *
 ./ ADD NAME=IEFSSNBB,LIST=ALL
 SUBSYS SUBNAME(DPSS) INITRTN(APSADPSS) INITPARM(1)
 ./ ENDUP
 /*

Consider these:

• You can dynamically add the subsystem after the system IPL by using the following operator command:

  SETSSI ADD,SUBNAME=DPSS,INITRTN=APSADPSS,INITPARM=n

• PSF DPSS does not support any other dynamic subsystem functions.