Split-Screen and Multiple Views / Panels

ISPF split-screen mode allows you to view two panels or two views simultaneously, dramatically improving productivity when working with multiple files, comparing data, or referencing information while editing. Understanding how to use split-screen effectively is essential for efficient mainframe work. This tutorial covers how to open multiple panels, switch between views, and use split-screen mode effectively.

Split-screen is particularly valuable when you need to compare files, reference one file while editing another, view different parts of the same file, or work with multiple datasets simultaneously. Instead of switching back and forth between panels, split-screen lets you see both at once, making your work more efficient and reducing errors.

Understanding Split-Screen Mode

Split-screen mode divides your terminal screen into two areas, each of which can display a different panel, file, or view.

What Split-Screen Does

When you activate split-screen mode:

• Your screen is divided into two areas (typically top and bottom, or left and right)
• Each area can display a different panel, file, or view
• You can work in either area independently
• You can switch between areas to make one active
• Both areas remain visible and accessible

Split-Screen Layout

Split-screen typically divides the screen:

• Vertically: Top and bottom halves, each showing a different panel or file
• Horizontally: Left and right halves (less common, depends on ISPF version)
• Equal Split: Usually 50/50, though some systems allow resizing

The exact layout depends on your ISPF version and configuration.

Initiating Split-Screen Mode

To start split-screen mode, use PF2 (Split).

Using PF2 to Split

To initiate split-screen:

• Press PF2 (or F2) while viewing any ISPF panel
• ISPF divides the screen into two areas
• The current panel is displayed in one area
• The other area may show a blank panel or the same panel initially
• You can then open different content in each area

Initial Split-Screen State

When you first split the screen:

• One area shows the panel you were viewing
• The other area may be empty or show a default panel
• Your cursor is in one of the areas (the active area)
• You can navigate and open content in either area

Opening Multiple Panels

Once split-screen is active, you can open different panels or files in each area.

Opening Content in Split Areas

To open different content in each split area:

• Switch to an Area: Use PF9 (Swap) to switch to the area where you want to open content
• Navigate or Open: Navigate to menus, open files, or display panels in that area
• Work Independently: Each area operates independently—you can have different panels, files, or views in each
• Switch Back: Use PF9 again to switch back to the other area

Common Split-Screen Scenarios

Common ways to use split-screen include:

• Two Different Files: Open one file in the top area and a different file in the bottom area for comparison or reference
• Same File, Different Views: View the same file in both areas but at different locations (useful for referencing one part while editing another)
• File and Documentation: Open a file in one area and help or documentation in the other
• Editor and List: Open the editor in one area and a member list or dataset list in the other
• Two Editors: Open two different files for editing simultaneously

Switching Between Split Areas

PF9 (Swap) switches the active area between the two split-screen areas.

Using PF9 to Switch

To switch between split areas:

• Press PF9 (or F9) to swap to the other area
• Your cursor and active focus move to the other area
• You can then work in that area
• Press PF9 again to switch back

Active Area Indicators

ISPF typically indicates which area is active:

• Cursor position shows which area is active
• Some systems may highlight the active area
• Function keys operate on the active area
• Commands you enter affect the active area

Working in Each Area

When working in split-screen:

• Each area operates independently
• You can scroll, edit, and navigate in each area separately
• Function keys affect the active area
• You can perform different operations in each area
• Changes in one area don't affect the other area

Split-Screen Use Cases

Split-screen is valuable for many common tasks.

Comparing Files

Split-screen is excellent for comparing files:

• Open one file in the top area and another in the bottom area
• Scroll through both files simultaneously to compare them
• Identify differences, similarities, or needed changes
• Make edits in one area while referencing the other

Referencing While Editing

Split-screen helps when you need to reference information while editing:

• Open the file you're editing in one area
• Open reference material, documentation, or another file in the other area
• Reference the material while making edits
• Switch between areas as needed

Viewing Different Parts of the Same File

You can view different parts of the same file in split-screen:

• Open the same file in both areas
• Navigate to different locations in each area
• Reference one part of the file while editing another part
• Useful for large files where you need to see different sections

Working with Multiple Datasets

Split-screen enables working with multiple datasets:

• Open one dataset in one area and another dataset in the other area
• Copy information between datasets
• Compare dataset structures or contents
• Work with related datasets simultaneously

Exiting Split-Screen Mode

You can exit split-screen mode in several ways.

Methods to Exit Split-Screen

To exit split-screen mode:

• Press PF2 Again: Pressing PF2 again may exit split-screen mode (depending on ISPF version)
• Press PF3: Pressing PF3 in one area may close that area and exit split-screen
• Close One Area: Closing or exiting one of the split areas returns you to single-panel mode
• Navigation: Some navigation actions may automatically exit split-screen

What Happens When Exiting

When you exit split-screen:

• The screen returns to single-panel mode
• One of the areas becomes the full screen (typically the active area)
• The other area is closed
• Any unsaved changes in the closed area may be lost (depending on the panel type)
• You return to normal single-panel operation

Resizing Split Areas

Some ISPF versions allow you to resize split-screen areas.

Resize Capabilities

Resize capabilities vary by ISPF version:

• PF13/PF14: Some systems use PF13/PF14 to resize split areas
• Other Function Keys: Some systems may use different keys for resizing
• Command-Based: Some systems may support resize commands
• Not Available: Some ISPF versions don't support resizing—areas are fixed at 50/50

Checking Resize Options

To determine if resize is available:

• Check function key labels when in split-screen mode
• Press PF1 for help while in split-screen to see available options
• Check your ISPF documentation or system help
• Try PF13/PF14 or other potential resize keys

Best Practices for Split-Screen

Following best practices helps you use split-screen effectively:

• Use for Comparison: Use split-screen when you need to compare files or reference information
• Keep It Simple: Don't overuse split-screen—use it when it provides clear benefits
• Save Before Splitting: Save your work before entering split-screen to avoid losing changes
• Know Your Active Area: Always be aware of which area is active so you know where your actions will take effect
• Use PF9 Effectively: Master PF9 switching to move efficiently between areas
• Exit Properly: Exit split-screen properly to avoid confusion or lost work
• Practice: Practice using split-screen to become comfortable with it

Limitations of Split-Screen

Understanding split-screen limitations helps you use it appropriately:

• Two Areas Only: ISPF split-screen typically supports only two areas, not more
• Screen Size: Each area has limited screen space, which may make some content harder to read
• Resize Limitations: Resize may not be available or may be limited in some ISPF versions
• Some Panels May Not Split: Some panel types may not work well in split-screen mode
• Performance: Split-screen may have slight performance implications, though usually minimal

Explain Like I'm 5: Split-Screen

Think of ISPF split-screen like having two TV screens side by side:

• PF2 (Split) is like a magic button that splits your one big screen into two smaller screens, so you can watch two different shows at the same time!
• Two Areas means you have two screens—one on top and one on bottom (or side by side). Each screen can show something different.
• PF9 (Swap) is like a remote control that switches which screen you're controlling. You press it and suddenly you're controlling the other screen instead!
• Different Shows means you can have one file on one screen and a different file on the other screen, like watching two different TV shows at once.
• Exiting is like turning off one of the TVs, so you go back to having just one big screen again.

So split-screen is like having two computer screens in one, so you can look at two things at the same time without having to switch back and forth!

Practice Exercises

Complete these exercises to reinforce your understanding of split-screen:

Exercise 1: Split-Screen Basics

Practice basic split-screen operations: press PF2 to split the screen, use PF9 to switch between areas, open different files in each area, and exit split-screen. Become comfortable with the basic split-screen workflow.

Exercise 2: File Comparison

Use split-screen to compare two files. Open one file in the top area and another in the bottom area. Scroll through both files and identify differences. Practice using split-screen for comparison tasks.

Exercise 3: Reference While Editing

Practice referencing one file while editing another. Open a file to edit in one area and reference material in the other area. Make edits while referencing the other area. Practice switching between areas as needed.

Exercise 4: Same File, Different Views

Open the same file in both split areas. Navigate to different locations in each area. Practice viewing different parts of the same file simultaneously. Use this to reference one part while editing another.

Exercise 5: Split-Screen Workflows

Create workflows that use split-screen effectively. For example, compare files, make edits based on comparison, reference documentation while coding, or work with multiple related datasets. Practice until split-screen becomes a natural part of your workflow.

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