Commodore 128 Programmer's Reference Manual page 506

11
u
496 COMMODORE 128
U
KEYBOARD SCANNING
\ j
The keyboard scan routine that is called to get a keyboard character returns the key code o
of the pressed key, or a code indicating that no key is currently being pressed. The
keyboard scan code is also responsible for handling programmable keys, programmable ) i
function keys, setting character and background colors, selecting MFM disk formats and <J
selecting current screen emulation type.
Any key on the keyboard can be defined to generate a code or function except the
following keys: 1
LEFT SHIFT
RIGHT SHIFT }
SHIFT LOCK L
G
CONTROL s |
RESTORE (8502 NMI)
40/80 DISPLAY
CAPS LOCK KEY
The keyboard recognizes the following special functions: 1)
Cursor left key-Used to define a key
Cursor right key-Used to define a string \
(points to function keys)
ALT key-Used as toggle key filter :
To indicate these functions, hold down the CONTROL key and the *->
RIGHT SHIFT key and simultaneously press the desired function key.
DEFINING A KEY _
The KEYFIG utility program allows the user to define the code that a key can produce. .
Each key has four modes of use for this function: j
■ Normal
■ Alpha shift , ,
■ Shift j
■ Control U
The alpha shift mode is toggled on/off by pressing the Commodore (O) key. When 1
this mode is turned on, a small white box appears on the bottom of the screen. The first o
key that is pressed thereafter is the key to be defined. The current hex value assigned to
this key is displayed, and the user can then type the new hex code for the key, or abort
by typing a non-hex key. The following is a definition of the codes that can be assigned i
to a key. See KEYFIG HELP for more information. ^