3.2. Keyboard Devices.   

Normal Keyboard: Switches arranged in standard pattern of keyboard. Useful for interaction in a controlled way -> software must be aware of need to echo if in graphics mode. Most keyboards are QWERTY giving ASCII code.

Special button devices can be arranged on a black box so that special functions may be invoked without the use of a normal keyboard. There may also be buttons associated with other input devices such as the light pen.

Keyboard Cursor Switches
It is possible to have a keyboard act like a joyswitch (see later section). Many intelligent VDU's have cursor control and have arrow buttons: 


                <-   ->   V   ^

These are used to position the cursor on the screen. (See Appendix A - Information on the Teleray model 1061.) 

 Some graphics terminals use these to position the graphics cross hair.

These keys move cursor 1 pixel in appropriate direction.

Usually there is facility for larger increment step.

(In gigi, use SHIFT key.)

Most modern workstations use a modified PC keyboard - these have the standard QWERTY layout with 10 or more function keys (normally programmable to send different text strings), a CAPS Lock, SHIFT, CONTROL and ALT keys as well as a numeric keypad, arrow buttons and Insert, Home, PageUp, PageDown, Delete and End buttons.

Many of the peripheral keys can be programmed or modified in an X Window System environment to perform complex actions via a single keystroke. Often the action can be modified via the CONTROL, SHIFT, or ALT buttons. (See the second X Window System tutorial for information on how to do this in a Motif environment).