A 21st Century z/OS ISPF Environment
by Jim Moore

The list of individually customizable options for ISPF is a large and ever-growing list. At first glance, the sheer number of options can be daunting. Perhaps this is why so many sites elect to "go with the defaults" as shipped by IBM in load module ISPCFIG.

However, if the options are examined and explained, the most critical ones can be brought to the fore. This will allow individual sites to choose wisely when selecting ISPF customization settings.

Since all of IBM's documentation is freely available on their web site, detailed information regarding the many ISPF customization keywords will not be repeated here. Please refer to the z/OS R1V2 – R1V4 Planning and Customizing book to view the actual IBM documentation referenced here.

User-Specific Customization - Defaults for the Settings Screen
The following keywords in the ISPF Configuration Table all apply to the initial default settings that each user will have applied to their ISPF profile. Most of these options can then be altered by individual ISPF users to suit their own taste at ISPF main menu Option 0 – Settings. Each one of these options also has a matching "RESET" option.

The RESET keywords pertain to how each user's profile is reset after an increment to the keyword VERSION_LEVEL_OF_SITEWIDE_DEFAULTS. When this value is incremented, ISPF will recognize that a change has been made to the site-wide settings. If the RESET keyword values are all set to NO, no existing values that users have previously customized will be reset to the new default. Any RESET value that has been set to YES, will cause that particular option to be reverted to the site-wide default at the next initial entry into ISPF.

Do not confuse RESET with FORCE. Several ISPF customization options have a FORCE setting which makes the option non-modifiable at the individual user level.

Here are our recommended defaults for the values at the Settings screen of z/OS V1R2 and higher:

Of course, if your site requires the Euro symbol enabled or is using the Session Manager interface, you will want to deviate from these suggestions. In the settings shown above, where our recommendation differs from IBM's default, an asterisk has been placed to the right of the option. All of the Settings screen options are shown here to get a complete picture of them. For a complete explanation of these options, please refer to the IBM documentation.

Here are a few more recommendations for several other defaults that fall into the "user-modifiable" Settings category:

CSR is recommended as a default scroll value (for all of IBM's scrollable fields) because it is more flexible than PAGE. With CSR as the default, if the cursor is anywhere outside of the scrollable portion of the screen (in the Command Line, for instance), CSR behaves like PAGE.

The IBM default for the primary menu Status area is SES. The calendar is far more useful. The SES display can always be viewed by using the SAREA command or changing the Status area from the primary menu.

The pad character default, when set to N, pads all input fields with nulls. The default is B (Blanks). Having blanks as the pad character causes ISPF users to constantly use the Erase EOF key if they need to insert anything into the command line. Having the default pad character set to nulls prevents this wasted effort.

The Normal Entry Field is a CUA color element. By default, it is set to 504. This indicates turquoise (5), low intensity (0) and underscore (4). Unless you want to see ISPF screens full of underscores, it is recommended that the Normal Entry Field has the underscore formatting removed.

In upcoming issues of the TSO Times, the many possible default settings of individual ISPF edit profiles and edit settings will be covered. They are numerous and truly require their own special treatment. Considering that most ISPF users spend up to 90% of their ISPF work day in the editor, taking the time to set up edit defaults will pay large dividends in productivity.

Site-Wide Customization - Settings That Cannot Be Altered at User Level
This category of site-specific customization needs careful thought, execution and planning. This is because the values established for these options cannot be changed by individual ISPF users and in general, will apply to every ISPF session on ALL logical screens.

Jumping right in, here are the "big ticket items". A discussion of each follows.

Interestingly, the Disallow Wildcards in HLQ option is set to NO by default. So why is it being listed here if our recommendation is the same as the default? Because some sites might want to alter this setting to YES. This option applies to the DSNAME mask at any DSLIST-type of search (typically, Option 3.4 and Option 11). Allowing wildcards (asterisks and percent-signs) to appear in the high level qualifier of a catalog search can degrade catalog access times if many ISPF users all use this type of search at the same point in time. Our recommendation is to keep it set to NO but keep an eye on its usage.

The Maximum Number of Split Screens setting has a default of eight. It can be set as high as 32. The extra overhead to create a sub-task for each logical screen is fairly minimal—some extra chaining in the IKJEFT01 TCB, an attached TCB and some other minor memory housekeeping. Some ISPF users may use more memory than they otherwise would with so many screens available but no extra overhead is required if an individual user never starts the maximum number of screens. Try 12 as a starting point—slightly above the default but nowhere near the maximum of 32.

The next three options are all related to one another and need a bit of historical context in order to fully grasp their usefulness.

[Read this link] for more information on IBM's latest implementation of ISPF command tables.

Having a site command table that is separate from the IBM delivered ISPCMDS saves a lot of unnecessary maintenance when a new release of ISPF comes out. Keeping your own commands in a SITECMDS table preserves all of your customization from release to release without the need to modify the ISPCMDS table.

The USERCMDS table is another nice touch. This options allows each user to create their own command table and place it in their ISPTTLIB (table input) concatenation. It is not for every ISPF user but knowledgeable ones will surely exploit this feature.

Note also that if no table named SITECMDS (or USERCMDS) is present when ISPF is started, this is not considered an error. ISPF will simply ignore the fact that no SITE/USER command table is in place. This allows a site to implement the separate tables at their own pace.

The Site Command Table Search Order should be set to AFTER. This is because of the frequency of searching involved with ISPCMDS. Since IBM's Type-1 commands (SPLIT, SWAP, UP, DOWN, etc.) are entered far more frequently than any site specific commands (under normal usage), why place the SITECMDS search ahead of the ISPCMDS search? The answer is: Don't place it BEFORE, which is the default.

If a USERCMDS table is present, it is always searched before the system or SITE command table. There is no option to move the USERCMDS table search order around as there is with SITECMDS. If an IBM or SITE command needs to be overridden, its entry can always be placed in an individual's USERCMD table.

The Retrieve Command Stack Size determines the amount of storage (in bytes) that is allocated to each ISPF user for their RETRIEVE stack. This is a push-down stack of typed (not PF-Key entered) ISPF commands that are accessible to the RETRIEVE, CRETRIEV, RETP and RETF ISPF commands. The default of 512 bytes is a bit stingy. This stack can be extremely useful and we recommend making it at least 1K in size. This storage is acquired as 24-bit as of z/OS V1R4.

Conclusion
This discussion of ISPF customization will be an on-going feature here at the TSO Times. As new customization items are added, they will be discussed. There is also a lot of explanation required for the numerous edit profile default settings and their associated FORCE keywords. Watch this space for much, much more on the value of a well-thought out ISPF customization plan.

Sample Configuration Table Keyword

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