Text-Terminal-HOWTO Text-Terminal-HOWTO David S. Lawyer, mailto:[e-mail] v1.01, October 1998This document explains what text terminals are, how they work, how to install and configure them, and provides some info on how to repair them. It may be of some use even if you don't have a terminal manual. While it's written for real terminals on a Linux system, some of it is also applicable to terminal emulation and may be helpful for non-Linux systems.1. Introduction1.1 Copyright, Trademarks, Disclaimer, & Credits1.2 Future Plans: You Can Help1.3 New Versions of this HOWTO1.4 Related HOWTO's1.5 Terminology Used in this Document1.6 What is a Terminal ?2. Types of Terminals2.1 Dumb Terminals2.2 Text Terminals2.3 Graphics Terminals2.4 Quasi-Terminals (= Quasi-Computers)2.5 Emulation on a PC3. Quick Install4. Why Use a Terminal ?4.1 Introduction4.2 Lower Hardware Costs4.3 Control of Software4.4 Hardware Upgrades4.5 Other Advantages of Terminals4.6 Major Disadvantages of Terminals4.7 Are Text Terminals Obsolete ?5. Overview of How Terminals Work (in Linux)5.1 Device Names5.2 Login/Logout5.3 Half/Full Duplex5.4 Terminal Memory5.5 Commands for the Terminal5.6 Lack of Standardization Solved by Terminfo5.7 The Interface5.8 Emulation5.9 The Console6. Terminal Special Files: /dev/tty... etc.6.1 Serial Port Terminals6.2 Pseudo Terminals6.3 The Controlling Terminal /dev/tty6.4 /dev/ttyIN "Terminals"6.5 The Console: /dev/ttyN6.6 Creating a Device with mknod7. Some Details on How Terminals Work7.1 Terminal Memory7.2 Early Terminals7.3 Escape Sequences and Control Codes (intro)7.4 Display Attributes & Magic Cookies8. Special Features of Some Terminals8.1 Color8.2 Dual Sessions8.3 Printer/Auxiliary Port8.4 Pages8.5 Character-Sets8.6 Fonts8.7 Keyboards & Special Keys9. Terminal Emulation; the Console9.1 Terminal Emulation9.2 The Linux Console10. Flow Control (Handshaking)10.1 Why Is Flow Control Needed ?10.2 Padding10.3 Overrunning a Serial Port10.4 Stop Sending10.5 Keyboard Lock10.6 Resume Sending10.7 Hardware Flow Control (RTS/CTS etc.)10.8 Is Hardware Flow Control Done by Hardware ?10.9 Obsolete ?? ETX/ACK or ENQ/ACK Flow Control11. Physical Connection11.1 Multiport I/O Cards (Adapters)11.2 Direct Cable Connection.11.3 Modem Connection11.4 Terminal Server Connection11.5 Connector and Adapter Types11.6 Making or Modifying a Cable12. Set-Up (Configure) in General12.1 Introduction12.2 Terminal Set-Up (Configure) Overview12.3 Computer Set-Up (Configure) Overview12.4 Many Options12.5 Communication Interface Options12.6 Quick Attempt13. Terminal Set-Up (Configure) Details13.1 Send Escape Sequences to the Terminal13.2 Older Terminals Set-Up13.3 Getting Into Set-Up (Configuration) Mode13.4 Communication Options13.5 Saving the Set-up13.6 Set-Up Options/Parameters13.7 Emulation {Personality} {{Terminal Modes}}13.8 Display Options13.9 Page Related Options13.10 Reporting and Answerback13.11 Keyboard Options13.12 Meaning of Received Control Codes13.13 Where New Text Goes13.14 Function Keys13.15 Block Mode Options13.16 Locks13.17 Screen Saver {Scrn Saver}13.18 Printer14. Computer Set-Up (Configure) Details14.1 Getty (in /etc/inittab)14.2 Stty & Setserial14.3 Terminfo & Termcap (brief)14.4 Setting TERM and TERMINFO14.5 Rarely Needed /etc/ttytype File14.6 Login Restrictions14.7 Run Command Only If TERM=my_term_type15. Terminfo and Termcap (detailed)15.1 Introduction15.2 Terminfo Database15.3 Modifying Terminfo Files15.4 Init String15.5 TERM Variable15.6 Terminfo/Termcap Documents16. Using the Terminal16.1 Introduction16.2 Starting Up the Terminal16.3 Terminal Device Driver16.4 Problems with Editors16.5 Display Freezes (hung terminal)16.6 Corrupted Terminal Interface16.7 Special (Control) Characters16.8 Viewing Latin-1 Files on a 7-bit Terminal16.9 Inspecting the Interface16.10 Changing the Terminal Settings16.11 Make a Terminal the Console17. Trouble-Shooting (software)17.1 Terminal Was Working OK17.2 Terminal Newly Installed17.3 Is the Terminal OK ?17.4 Missing Text17.5 Getty Respawning Too Rapidly17.6 Fails Just After Login17.7 Can't Login17.8 Garbled Login Prompt17.9 No Sign of any Login Prompt17.10 Serial Monitoring/Diagnostics17.11 Local Mode17.12 Serial Electrical Test Equipment18. Repair & Diagnose18.1 Repair Books & Websites18.2 Safety18.3 Appearance of Display18.4 Diagnose18.5 Capacitors18.6 Keyboards19. Appendix A: General19.1 List of Linux Terminal Commands19.2 The Internet and Books19.3 Non-Linux OS's20. Appendix B: Escape Sequence Commands Terminology20.1 Esc Sequence List20.2 Printer Esc20.3 Reports20.4 Cursor Movements20.5 Pages21. Appendix C: Serial Communications on EIA-232 (RS-232)21.1 Introduction21.2 Voltages21.3 Parity Explained21.4 Forming a Byte (Framing)21.5 Limitations of EIA-23221.6 Synchronization & Synchronous21.7 Block Mode21.8 EIA-232 (RS-232) Books21.9 Serial Software22. Appendix D: Notes by Brand Name22.1 CIT22.2 IBM22.3 Teletypes22.4 VT (DEC)22.5 Wyse