Column and Margin Manipulation

Column and margin manipulation in ISPF involves setting and working with column boundaries, margins, and column positions. The BOUNDS command sets editing boundaries, while columns commands help you work with fixed-format files where specific columns have meaning. This tutorial covers BOUNDS, column manipulation, margin settings, and techniques for working with column-based formatting.

Understanding column and margin manipulation is essential for working with fixed-format languages like COBOL, where specific columns have specific meanings. Proper column boundaries ensure you maintain correct formatting and avoid errors from text extending beyond allowed columns.

Understanding Columns and Margins

Columns and margins define the editable area and help maintain proper formatting.

What are Columns?

Columns are:

• Vertical positions in a line
• Numbered from left to right (typically 1-80 or 1-132)
• Important for fixed-format languages
• Used to position text correctly

What are Margins?

Margins are:

• Left and right boundaries of the editable area
• Defined by column positions
• Restrict where you can type
• Help maintain proper formatting

Why Columns and Margins Matter

Columns and margins are important because:

• Fixed-format languages have column requirements
• COBOL uses specific column areas (Area A, Area B)
• Record length limits must be respected
• Proper formatting ensures code compiles correctly

BOUNDS Command

The BOUNDS command sets the left and right column boundaries for editing.

Basic BOUNDS Syntax

Basic syntax:

1
BOUNDS leftcolumn rightcolumn

Where leftcolumn is the left boundary and rightcolumn is the right boundary.

BOUNDS Examples

Setting boundaries for full-width editing (columns 1-72):

1
Command ===> BOUNDS 1 72

Setting boundaries for COBOL Area B (columns 12-72):

1
Command ===> BOUNDS 12 72

Setting boundaries for a specific range (columns 8-72):

1
Command ===> BOUNDS 8 72

BOUNDS Behavior

When BOUNDS is set:

• Editing is restricted to the specified column range
• You cannot type outside the boundaries
• Boundaries are enforced visually and functionally
• Boundaries persist until changed or editor is closed
• Boundaries apply to all editing operations

Changing BOUNDS

You can change BOUNDS at any time:

• Use BOUNDS again with new column numbers
• New boundaries take effect immediately
• Previous boundaries are replaced
• You can adjust boundaries as needed during editing

COBOL Column Areas

Understanding COBOL column areas helps you set appropriate boundaries.

COBOL Column Structure

COBOL uses specific column areas:

1
2
3
4
5
Columns 1-6:   Sequence Number Area (optional)
Column 7:     Indicator Area (continuation, comment, etc.)
Columns 8-11: Area A (division, section, paragraph names, level numbers)
Columns 12-72: Area B (procedure statements, data descriptions)
Columns 73-80: Identification Area (optional, for sequence numbers)

BOUNDS for COBOL

Common BOUNDS settings for COBOL:

• BOUNDS 1 72: Full editing range (most common)
• BOUNDS 12 72: Area B only (for procedure statements)
• BOUNDS 8 72: Area A and Area B
• BOUNDS 1 80: Full width including identification area

When to Use Each BOUNDS Setting

Use different BOUNDS settings based on what you're editing:

• BOUNDS 1 72: General COBOL editing, allows access to all areas
• BOUNDS 12 72: When writing procedure statements in Area B
• BOUNDS 8 72: When working with Area A and Area B
• BOUNDS 1 80: When you need the full record width

Column Display

Column display helps you see column positions while editing.

Column Markers

Column markers may be displayed as:

• Column numbers at the top or bottom of the data area
• Vertical lines marking specific column positions
• Highlighted columns for important positions
• Column rulers showing column positions

Enabling Column Display

Column display can be enabled through:

• ISPF Settings (Option 0)
• Editor display options
• Panel-specific configurations
• Function keys or commands (depending on ISPF version)

Column Display Benefits

Column display helps you:

• See exact column positions
• Position text correctly
• Stay within column boundaries
• Understand where different areas begin and end

Margin Settings

Margins define the left and right boundaries of the editable area.

Left Margin

The left margin:

• Defines where text starts when you type
• Typically starts at column 1, but can be configured
• Can be set through BOUNDS or editor settings
• Important for fixed-format languages

Right Margin

The right margin:

• Defines where text ends
• Typically corresponds to record length (LRECL)
• Helps you stay within record length limits
• Important for fixed-format languages where specific columns mark the end

Setting Margins

Margins can be set through:

• BOUNDS command (sets both left and right)
• ISPF Settings for default margins
• Editor profile settings
• Panel-specific configurations

Column-Based Operations

Some operations work with specific columns.

Column Positioning

When positioning text by column:

• Use column markers to see positions
• Type or move text to specific columns
• Ensure text starts at the correct column
• Verify text doesn't extend beyond boundaries

Column Alignment

For column alignment:

• Use spaces to position text at specific columns
• Use column markers as guides
• Ensure consistent alignment
• Verify alignment is correct for your format

Working with Fixed-Format Files

Fixed-format files require careful column management.

COBOL Editing

When editing COBOL:

• Set appropriate BOUNDS (typically 1 72)
• Position division/section names in Area A (columns 8-11)
• Position procedure statements in Area B (columns 12-72)
• Use column 7 for continuation or comment indicators
• Ensure lines don't extend beyond column 72

JCL Editing

When editing JCL:

• JCL statements typically start at column 1
• Continuation lines use column 72 for continuation indicator
• Set BOUNDS appropriately (typically 1 72)
• Respect column positions for proper JCL syntax

Other Fixed-Format Files

For other fixed-format files:

• Understand the column requirements
• Set BOUNDS to match the format
• Use column markers to maintain alignment
• Respect record length limits

Best Practices

Following best practices helps you work with columns and margins effectively:

• Set BOUNDS Early: Set appropriate BOUNDS when you start editing
• Use Column Markers: Enable column markers to see positions
• Understand Format Requirements: Know the column requirements for your file type
• Respect Boundaries: Stay within BOUNDS to avoid formatting errors
• Adjust as Needed: Change BOUNDS when switching between different areas
• Verify Column Positions: Check that text is positioned correctly
• Use Appropriate Settings: Set BOUNDS based on what you're editing
• Test Formatting: Verify formatting is correct for your file type

Common Scenarios

Here are common scenarios for column and margin manipulation.

Editing COBOL Procedure Statements

When editing COBOL procedure statements:

• Set BOUNDS 12 72 for Area B
• Position statements starting at column 12
• Ensure statements don't extend beyond column 72
• Use column markers to verify positions

Editing COBOL Data Descriptions

When editing COBOL data descriptions:

• Set BOUNDS 1 72 for full range
• Position level numbers in Area A (columns 8-11)
• Position data descriptions in Area B (columns 12-72)
• Maintain proper column alignment

Switching Between Areas

When switching between COBOL areas:

• Change BOUNDS as needed
• Use BOUNDS 8 72 when working with both Area A and Area B
• Use BOUNDS 12 72 when working only in Area B
• Adjust boundaries based on current editing needs

Column Commands Reference

Here are common column-related commands and operations.

BOUNDS Command

Primary command for setting column boundaries:

1
BOUNDS leftcolumn rightcolumn

Column Display Toggle

Some ISPF versions support toggling column display. Check your ISPF documentation for available commands.

Column Navigation

You can navigate by column using:

• Cursor movement keys
• Column positioning commands (if available)
• Status line to see current column position

Error Prevention

Preventing errors when working with columns and margins.

Common Mistakes

Avoid these common mistakes:

• Wrong BOUNDS Settings: Use appropriate BOUNDS for your file type
• Text Beyond Boundaries: Ensure text stays within BOUNDS
• Wrong Column Positions: Verify text is positioned at correct columns
• Ignoring Format Requirements: Respect column requirements for your format
• Not Using Column Markers: Enable column markers to see positions

Recovery Strategies

If you make mistakes:

• Adjust BOUNDS: Change BOUNDS if you set incorrect boundaries
• Reposition Text: Move text to correct column positions
• Use Column Markers: Enable column markers to verify positions
• Review Format Requirements: Check format requirements and adjust accordingly

Explain Like I'm 5: Column and Margin Manipulation

Think of columns and margins like lines on a piece of paper:

• Columns are like the numbers on a ruler. Each number tells you "this is position 1, this is position 10, this is position 50!" They help you know exactly where you are on the line, like using a ruler to measure where to put things.
• Margins are like the edges of your paper. The left margin is like the left edge where you start writing, and the right margin is like the right edge where you stop. They keep your writing in the right place, like the edges of a piece of paper!
• BOUNDS is like drawing lines on your paper. You say "you can only write between line 1 and line 72!" It's like drawing boundaries and saying "stay inside these lines!" This helps make sure everything is in the right place.
• Column Areas are like different sections of your paper. In COBOL, there's Area A (like one section) and Area B (like another section). Each section has its own rules about where you can write, like having different areas on a form!

So column and margin manipulation is like having special guides and boundaries that help you write in exactly the right places on your "paper" (file), making sure everything is positioned correctly!

Practice Exercises

Complete these exercises to reinforce your understanding of column and margin manipulation:

Exercise 1: Setting BOUNDS

Practice setting BOUNDS: try different BOUNDS settings (1 72, 12 72, 8 72), observe how boundaries affect editing, and practice changing BOUNDS during editing. Build familiarity with boundary settings.

Exercise 2: Column Positioning

Practice column positioning: enable column markers if available, practice positioning text at specific columns, work with fixed-format files, and verify text is positioned correctly. Master column-based positioning.

Exercise 3: COBOL Area Editing

Practice COBOL area editing: set BOUNDS for Area A and Area B, practice positioning division/section names in Area A, practice positioning procedure statements in Area B, and verify column positions are correct.

Exercise 4: Margin Management

Practice margin management: understand left and right margins, set margins through BOUNDS, observe how margins affect editing, and practice working within margin boundaries.

Exercise 5: Format-Specific Editing

Practice format-specific editing: work with COBOL files using appropriate BOUNDS, work with JCL files, understand column requirements for different formats, and apply appropriate boundary settings.

Related Concepts