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Text-Terminals on Linux

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13.11 Keyboard Options

Keyclick

When set, pressing any key makes a click (broadcast by a tiny loudspeaker in the keyboard). These clicks annoy some people and I think it's best to set keyclick off.

Caps Lock {Keylock}

When the Caps-Lock key is down, should only the alphabetic keys generate shifted characters? If set to {Caps} or upper-case-only then hitting a number key with the Caps-Lock on will type the number. To get the symbol above the number one must manually hold down the shift key. This is the normal mode. If set to {Shift} then all keys type the shifted character when Caps-Lock is on (hitting the 5 key should type % without holding down Shift, etc.).

Auto Repeat {Repeat}

If a key is held down then that key is repeatedly "typed". This is handy for repeatedly typing the same character to create a line across the page.

Margin Bell

When the cursor is 8 columns away from the right side of the display, a bell is rung (like on an old typewriter). Almost all editors will automatically create a new line if needed (no need to hit the Return key) so this feature is seldom needed.

Remapping the Keys

The code sent to the host when a key is pressed is normally the ASCII code for that key (depends also on Shift and Control key). On some terminals you may make any key send any code you wish. That is, you may completely remap the keyboard by setting up the terminal that way. This may be useful for some foreign languages and Dvorak keyboard layouts, etc. which permit one to type faster. Even for terminals that don't have the feature, there is software to remap the keyboard (and screen also). It's something like a device driver which uses a pseudo terminal. See Character Mapping: mapchan

Corner Key (for Wyse only)

Wyse terminals have a key near the lower left corner which may be set to do various things. Its may be labelled "Funct", "Compose Character", "Alt", "Hold" or "Scroll Lock". Early models don't have all of the following options:

  • Hold: No-Scroll. Hitting it stops the flow of data (using flow control) to the terminal. Hitting the key again restores normal flow.
  • Compose: Hitting it followed by certain other keys permits one to generate a limited number of pre-defined non-Latin characters.
  • Meta: Holding it down while typing another key sets the high-order bit on each byte. Are there models where it acts like a toggle to lock in the meta effect ??
  • Funct: Holding it down while typing any alphanumeric key gets a header (SOH) and trailer (CR) byte framing the ASCII byte code.
  • Kpd Compose: Holding it down while typing a decimal number on the numeric keys (followed by "enter") sends out the same number in hexadecimal ??

Numeric Keypad or Arrow Keys Sends

The numeric keypad (the rectangle of mostly numeric keys to the right of the main part of the keyboard) can be set to send special codes which will do special things in certain application programs. Ditto for the arrow keys. There is thus a "normal" mode where they send what is shown on the keycap (or the normal code sequence for an arrow-key) and an "application" mode where special escape sequences are sent. In some cases there is a "hex" numeric mode which is almost like normal numeric mode except that 6 non-numeric keys send the letters A-F. Thus one may type for example "B36F" on the numeric keypad.

What does shifted-del and shifted-bs send?

Depending on how they're set up, shifted-del sometimes sends the control character CAN and shifted backspace sometimes sends DEL.

PC Scan Codes

Many terminals can emulate a PC keyboard by sending PC scancodes (see Keyboard-and-Console-HOWTO) instead of ASCII codes. This is mostly used with special Multiuser DOS OSs. It won't work with ordinary MS DOS. See Non-Linux OSs However, hardly any Linux programs that run via the serial port can accept scancodes. If this is the latest version of this HOWTO, let me know if any programs do this. I think

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* Text Terminal How-To Index

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