Contents

Introduction

Chapter 1 - Terminal Overview

• 1.1 General
• 1.2 Terminal Characteristics and Capabilities
  • 1.2.1 Display Characteristics and Capabilities
  • 1.2.2 Text Capabilities
• 1.3 Communication Environment
• 1.4 Major Operating States
• 1.5 Major Operating Modes

Chapter 2 - Character Encoding

• 2.1 General
• 2.2 Coding Standards
• 2.3 Code Table
  • 2.3.1 7-Bit ASCII Code Table
  • 2.3.2 8-Bit Code Table
• 2.4 Character Sets
  • 2.4.1 DEC Multinational Character Set
  • 2.4.2 U.K. National Set
  • 2.4.3 DEC Special Graphics Set
  • 2.4.4 Down-Line Loadable Character Set
• 2.5 Control Functions
  • 2.5.1 Escape Sequences
  • 2.5.2 Control Sequences
  • 2.5.3 Device Control Strings
• 2.6 Working with 7- and 8-Bit Environments
  • 2.6.1 Conventions for Codes Transmitted to the Terminal
  • 2.6.2 Conventions for Codes Transmitted by the Terminal
• 2.7 Display Controls Mode

Chapter 3 - Transmitted Codes

• 3.1 General
• 3.2 Keyboard Codes Generated
  • 3.2.1 Main Keypad
    • 3.2.1.1 Standard Keys
    • 3.2.1.2 Function Keys
  • 3.2.2 Editing Keypad
  • 3.2.3 Auxiliary Keypad
  • 3.2.4 Top-Row Function Keys
  • 3.2.5 Control Codes Generated
• 3.3 Enabling and Disabling Autorepeat
• 3.4 Keyboard Lock and Unlock

Chapter 4 - Received Codes

• 4.1 General
• 4.2 Control Characters
• 4.3 Compatibility Level (DECSCL)
• 4.4 Character Set Selection (SCS)
  • 4.4.1 Designating "Hard" Character Sets
  • 4.4.2 Designating "Soft" (Down-Line Loadable) Character Sets
  • 4.4.3 Invoking Character Sets Using Locking Shifts
  • 4.4.4 Invoking Character Sets Using Single Shifts
    • 4.4.4.1 SS2 -- Single Shift G2
    • 4.4.4.2 SS3 -- Single Shift G3
• 4.5 Select C1 Controls
  • 4.5.1 Select 7-Bit C1 Control Transmission (S7C1T)
  • 4.5.2 Select 8-Bit C1 Control Transmission (S8C1T)
• 4.6 Terminal Modes
  • 4.6.1 Set Mode (SM)
  • 4.6.2 Reset Mode (RM)
  • 4.6.3 Keyboard Action Mode (KAM)
  • 4.6.4 Insert/Replacement Mode (IRM)
  • 4.6.5 Send-Receive Mode (SRM)
  • 4.6.6 Line Feed/New Line Mode (LNM)
  • 4.6.7 Text Cursor Enable Mode (DECTCEM)
  • 4.6.8 Cursor Key Mode (DECCKM)
  • 4.6.9 ANSI/VT52 Mode (DECANM)
  • 4.6.10 Column Mode (DECCOLM)
  • 4.6.11 Scrolling Mode (DECSCLM)
  • 4.6.12 Screen Mode (DECSCNM)
  • 4.6.13 Origin Mode (DECOM)
  • 4.6.14 Auto Wrap Mode (DECAWM)
  • 4.6.15 Auto Repeat (DECARM)
  • 4.6.16 Print Form Feed Mode (DECPFF)
  • 4.6.17 Print Extent Mode (DECPEX)
  • 4.6.18 Keypad Mode (DECKPAM/DECPNM)
• 4.7 Cursor Positioning
• 4.8 Tab Stops
• 4.9 Character Rendition and Attributes
  • 4.9.1 Select Graphic Rendition (SGR)
  • 4.9.2 Select Character Attributes (DECSCA)
• 4.10 Line Attributes
  • 4.10.1 Double Height Line (DECDHL)
  • 4.10.2 Single-Width Line (DECSWL)
  • 4.10.3 Double-Width Line (DECDWL)
• 4.11 Editing
• 4.12 Erasing
• 4.13 Scrolling Margins (Top and Bottom)
  • 4.14 Set Top and Bottom Margins (DECSTBM)
• 4.14 Printing
• 4.15 User Defined Keys (DECUDK)
  • 4.15.1 DECUDK Device Control String Format
  • 4.15.2 Things to Keep in Mind When Loading Keys
  • 4.15.3 Examples and Recommendations for Using DECUDK
• 4.16 Down-Line Loadable Character Set
  • 4.16.1 Designing a Character Set
  • 4.16.2 Down-Line Loading DRCS Characters
  • 4.16.3 DECDLD Example
  • 4.16.4 Clearing a Down-Line Loaded Character Set
• 4.17 Reports
  • 4.17.1 Device Attributes (DA)
  • 4.17.2 Device Status Report (DSR)
  • 4.17.3 Identification (DECID)
• 4.18 Terminal Reset (DECSTR and RIS)
  • 4.18.1 Soft Terminal Reset (DECSTR)
  • 4.18.2 Hard Terminal Reset (RIS)
• 4.19 Tests and Adjustments (DECTST and DECALN)
  • 4.19.1 Tests (DECTST)
  • 4.19.2 Adjustments (DECALN)
• 4.20 VT52 Mode Escape Sequences

Appendix A - VT220/VT102 Differences

Appendix B - Additional VT220 Documentation

Tables

• 2-1 7-Bit ASCII Code Table
• 2-2 8-Bit Code Table
• 2-3 DEC Multinational Character Set
• 2-4 DEC Special Graphics Character Set
• 2-5 British NRC Set
• 2-6 Dutch NRC Set
• 2-7 Finnish NRC Set
• 2-8 French NRC Set
• 2-9 French Canadian NRC Set
• 2-10 German NRC Set
• 2-11 Italian NRC Set
• 2-12 Norwegian/Danish NRC Set
• 2-13 Spanish NRC Set
• 2-14 Swedish NRC Set
• 2-15 Swiss NRC Set
• 2-16 Display Controls Font
• 3-1 Codes Generated by Editing Keys
• 3-2 Codes Generated by Cursor Control Keys
• 3-3 Codes Generated by Auxiliary Keypad Keys
• 3-4 Codes Generated by Top Row Function Keys
• 3-5 Keys Used to Generate 7-Bit Control Characters
• 4-1 C0 (ASCII) Control Characters Recognized
• 4-2 C1 Control Characters Recognized
• 4-3 Level 1-Level 2 Compatibility Comparison
• 4-4 Designating "Hard" Character Sets
• 4-5 Invoking Characters Sets Using Lock Shifts
• 4-6 Selectable Modes Summary
• 4-7 ANSI-Standardized Modes
• 4-8 ANSI-Compatible DEC Private Modes
• 4-9 DECDLD Parameter Characters
• 4-10 Soft Terminal Reset (DECSTR) States
• 4-11 VT52 Escape Sequences

Figures

• 1-1 VT220 Video Display Terminal
• 2-1 7-Bit Code
• 2-2 8-Bit Code
• 3-1 Key Grouping (North American Keyboard)
• 3-2 French/Belgian Keyboard
• 4-1 Character Set Selection
• 4-2 Locking and Single-Shift Commands (VT100 Mode)
• 4-3 Locking and Single-Shift Commands (VT200 Mode)
• 4-4 Cell and Normal Character Cell Size Relationship
• 4-5 Example of an "A" Character
• 4-6 Example of an "A" Divided Into Columns
• 4-7 Column Codes for Example 80-Column Font Character A