Technical Background Details for Setting up an Application under ETSO

Document ID : KB000055721
Last Modified Date : 14/02/2018
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Refer to the Advantage CA-Roscoe Extended Development Tools Guide for basic information about setting up an application under ETSO.

  • ETSO provides an LWA (Logon Work Area) that is chained from the ASCB.

  • Certain applications running under ETSO use the contents of the field PSCBUSER in the TSO control block named PSCB. Under TSO, this field is initialized to the TSO userid. To permit these applications to execute, a global pseudo-PSCB is provided which contains a PSCBUSER field. This field can be initialized by the Advantage CA-Roscoe PSCBUSER= initialization parameter to the first seven characters of the Advantage CA-Roscoe job name (the default) or any one- to seven-character string the site specifies. (This parameter is particularly important for JES3 sites using the local option.)

    Note: Command processors are not passed the address of the global pseudo-PSCB. They are passed the address of their own unique pseudo-PSCB. The field PSCBUSER in each unique pseudo-PSCB contains the user's prefix with the string 'ETSO' concatenated to it.

  • By default, SYSALLDA is the default unit name that is used by dynamic allocation when an allocation request is received that requires a unit name and none is specified. This name is placed in the PSCB control block created by ETSO when a user executes a TSO command processor. The Advantage CA-Roscoe initialization parameter PSCBUNIT= may be used to change the default unit name.

  • By default, an individual may allocate a maximum of 19 files per session. (This includes any combination of terminal, AWS, library member and/or external data sets.) The Advantage CA-Roscoe initialization parameter ETSOALLOC= may be use to set the maximum to a value between 1 and 32760.

  • ETSO supports a maximum of 10 files to be concatenated per ddname.

  • The ALLOCATE command uses SVC 99 to allocate all OS files. Sites have the option of:

    • Defining frequently accessed files within the Advantage CA-Roscoe JCL to eliminate the overhead involved in dynamic allocations. If this option is used, tell the appropriate users the names of the DD statements that define these data sets. They can then use these DD names with the JCLDD= operand of the ALLOCATE command, as in:
      If users do not identify the file through the JCLDD= operand, the file will be dynamically allocated.

    • Including text unit X'0061' in the SVC 99 parameters for all new data sets created with a permanent data set name. By default, text unit X'0061' is included only when the user issues the ALLOCATE command with PROTECT=YES. Sites that want to implement this should contact the Advantage CA-Roscoe technical | support staff for the USERMOD. If this change is made, users should not use the PROTECT= operand of the ALLOCATE command.

  • ETSO contains an extension that allows users to easily switch between the use of TSO facilities and native Advantage CA-Roscoe facilities. This TSO compatibility mode provides an environment for the continued execution of TSO commands, procedures, and products within Advantage CA-Roscoe, including those which have no Advantage CA-Roscoe counterpart.

  • Applications such as ISPF/PDF can run under Advantage CA-Roscoe, but sites remain responsible for those applications and must provide the application/service for the user.

  • Using the Advantage CA-Roscoe TSO command from the command line, or within an RPF, a user can invoke any TSO program or command. The ETSO compatibility mode allows these commands to be passed, as is, to the Advantage CA-Roscoe Command Processor, ROSTMP, which will invoke the appropriate TSO facility.

    Note: For information on the use of the TSO command, see the Advantage CA-Roscoe Interactive Environment Command Reference Guide.

  • Advantage CA-Roscoe runs as an APF authorized task. The use of an ISPLLIB or STEPLIB within either CLISTs or RPFs that call ISPF may result in an S306-C abend in ISPMAIN. The data sets allocated in the ISPLLIB or STEPLIB from a CLIST or RPF must be added to the Advantage CA-Roscoe ETSOLIB concatenation. If your linklist is authorized through LNKAUTH=LNKLST and ETSSRCH=ALL, no pre-allocation of ISPLLIB or STEPLIB will be necessary if the load library is found in the linklist.

  • Entering the Advantage CA-Roscoe TSO command activates ROSTMP through an OS ATTACH; or if ROSTMP is already active, it is signaled with new input. ROSTMP will invoke the appropriate TSO command processor and pass to it the parameters passed in the (Advantage CA-Roscoe) TSO command. ROSTMP remains active until TSO LOGOFF is specified.

  • This facility will not replace existing ETSO facilities (and the CALL command). The ETSO CALL command will remain a more specialized (and explicit) way to invoke a program in a TSO-compatible environment.
  • This compatibility mode will provide for the execution of CLISTs as well as REXX execs. Those procedures will be executable directly from the command line, from within each other (nesting), and from within ISPF dialogs. Both Explicit (EXEC) and Implicit (%) invocations are supported. When invoking CLISTs, to prevent extraneous information (garbage) from being displayed on your screen, include the following in the


  • For additional information, the profile ROSCOE.MAINT contains a variety of members that provide additional information about applications that execute under ETSO.

To evaluate what impact running application under ETSO will have on your environment, please see tecxxxx (and link to the following tech doc)