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HELP TTY Jonathan Laventhol, 4 October 1983 There are various keys on the terminal which perform important functions. These are dependent on the installation, and so in the documentation we call them by their function (written in upper case between angle brackets, e.g. <INTERRUPT>). Please check with your installation manager to find out which keys have which function on the machine you use. You can alter this in your login startup file, if necessary (using the Unix 'stty' command), but for details you will have to consult UNIX manuals. CONTENTS - (Use <ENTER> g to access required sections) -- Example key mappings -- <INTERRUPT> -- <QUIT> -- <END-OF-FILE> -- <SUSPEND> -- <ERASE> -- <KILL> -- <WORD-ERASE> -- <START> and <STOP> -- <RETURN> -- NOTE -- Example key mappings ----------------------------------------------- The following is a commonly used set of mappings of functions to keystrokes especially on DEC computers. <INTERRUPT> is <CTRL>-C <QUIT> is <CTRL>-Y <END-OF-FILE> is <CTRL>-Z (sometimes <CTRL>-D) <SUSPEND> is <CTRL>-\ (sometimes <CTRL>-Z) <ERASE> is DEL (a key marked del) <KILL> is <CTRL>-U <WORD-ERASE> is <CTRL>-W <START> is <CTRL>-Q <STOP> is <CTRL>-S <RETURN> is the RETURN key or <CTRL>-M The functions of the various keys is described below. -- <INTERRUPT> -------------------------------------------------------- This interrupts the computer, usually stopping whatever program is running, and returns you to some known and hopefully reassuring state. This is useful if you think the machine is ignoring you, or if you feel like stopping the program for some reason. Be careful though, because usually it isn't possible to get the program running again from where it left off -- you probably will have to restart it. Inside POPLOG you will get a message like "Setpop" or "Setlisp" which means that everything is under control. Otherwise you should get a helpful prompt back. In POPLOG you can alter the effect of the <INTERRUPT> key by assigning a suitable procedure value to the POP-11 variable INTERRUPT. See HELP *INTERRUPT -- <QUIT> ------------------------------------------------------------- Sometimes the <INTERRUPT> key doesn't appear to work, and you really think the machine is ignoring you. Then you can use the <QUIT> key, which really should stop the program in its tracks. If it doesn't, ask for help from a human. Sometimes this will leave a file called "core" in your directory, which you should remove or ignore. Inside POPLOG, the effect of pressing this key depends on whether you press it once, or do it twice in quick succession. Pressing it ONCE has the effect of invoking the procedure "setpop" which interrupts all running procedures and goes back to the "top level". It will generally leave you outside the editor, VED. (See HELP * SETPOP) Pressing it TWICE in very quick succession will make it leave POPLOG fairly abruptly. -- <END-OF-FILE> ------------------------------------------------------ This key usually means "okay, I've finished talking now". So you use this to leave POP-11 or PROLOG, for example, or to finish talking to the computer altogether. Sometimes you use it to finish typing a piece of text (for example, to the mail program). In VED this is often redefined to mean "move to end of current line". -- <SUSPEND> ---------------------------------------------------------- This is available only on Berkeley Unix systems and only if you are running the C-SHELL. This key is used if you want to keep the current program in suspended animation. It stops running, but it isn't dead yet. You go back to the CSH program (see HELP *SHELL). You can then run some other programs, and later come back to the frozen one when you want by typing a single percent sign to the shell prompt. If you suspend several processes you indicate which one you want by giving an integer, e.g. '%3' re-starts process 3. Only use the <SUSPEND> key if you know what you are doing because it can produce some very confusing behaviour. DON'T USE IT FROM VED AT PRESENT - it leaves the terminal in a funny state. Instead you can (on Berkeley Unix systems) get the same effect by doing: <ENTER> stop (See HELP * STOP) -- <ERASE> ------------------------------------------------------------ This is used to rub out the last character typed. This only works up to the last <RETURN> typed, so you can get rid of a character before you press the <RETURN> key, but not after. (In VED this restrinction doesn't apply.) -- <KILL> ------------------------------------------------------------- This is used to rub out the line which you are currently typing. Again, this usually only works before you press the RETURN key. -- <WORD-ERASE> ------------------------------------------------------- This is like the <KILL> key, but deletes the most recent "word" which you typed. (It doesn't really know about words, but it does make a good guess.) Like the <KILL> key and the <ERASE> key, this doesn't work after you've pressed the <RETURN> key. -- <START> and <STOP> ------------------------------------------------- When the computer is printing lots of stuff, oftentimes it will go off the screen before you get a chance to read it. You can press the <STOP> key to make it wait for you to catch up, and then the <START> key to make it print more. Watch out for the <STOP> key -- if you press it by mistake and don't know about it, the machine won't print anything and will look as though it's completely ignoring you. Try the <START> key before panicking. (Some terminals have a key marked 'SCRL' or 'No SCRL'. Pressing this alternately sends a <STOP> and a <START> code to the computer. -- <RETURN> ----------------------------------------------------------- When you are typing commands to a program or the shell, the <RETURN> key essentially says to the computer 'I have finished typing in this line, so take it and do what you have to with it'. The line may give a command, or it may be some input in response to a query from the program. Before you press the key you can "edit" what you have just typed by cancelling some or all of it using the <KILL> key, the <ERASE> key, or the <WORD-ERASE> key. After pressing <RETURN> it is too late. -- NOTE --------------------------------------------------------------- In VED some of the keys lose their normal effects or have additional effects. -----<Copyright University of Sussex 1987. All rights reserved.>-------