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