HP dx7300 Technical Reference Manual page 183

C.2.4 Keys
All keys generate a Make code (when pressed) and a Break code (when released) with the
exception of the
exception of the
Shift, Ctrl, Alt, Num Lock, Scroll Lock, Caps Lock
of the
the BIOS. Typematic keys, when held down longer than 500 ms, send the Make code repetitively
at a 10-12 Hz rate until the key is released. If more than one key is held down, the last key
pressed will be typematic.
C.2.4.1 Special Single-Keystroke Functions
The following keys provide the intended function in most applications and environments.
Caps Lock
—The
that turns on the caps lock LED and shifts into upper case key positions 40-49, 60-68, and 76-82.
When pressed and released again, these keys revert to the lower case state and the LED is turned
off. Use of the
Num Lock
—The
that turns on the num lock LED and shifts into upper case key positions 55-57, 72-74, 88-90,
100, and 101. When pressed and released again, these keys revert to the lower case state and the
LED is turned off.
The following keys provide special functions that require specific support by the application.
Print Scrn
—The
a print routine. This function may be inhibited by the application.
Scroll Lock
—The
routine that turns on the scroll lock LED and inhibits movement of the cursor. When pressed and
released again, the LED is turned off and the function is removed. This keystroke is always
serviced by the BIOS (as indicated by the LED) but may be inhibited or ignored by the
application.
Pause
—The
loop, i.e., wait for another key to be pressed. This can be used to momentarily suspend an
operation. The key that is pressed to resume operation is discarded. This function may be ignored
by the application.
Esc Fn
The , (function),
discretion of the application software.
C.2.4.2 Multi-Keystroke Functions
Shift Shift
—The
in positions 17-29, 30, 39-51, 60-70, and 76-85 as long as the
toggled off. If the
(normal) case for the identified pressed keys. The Shift key also reverses the
key positions 55-57, 72, 74, 88-90, 100, and 101.
Ctrl Ctrl
—The
17-34, 39-54, 60-71, and 76-84. The application determines the actual function. Both
positions provide identical functionality. The pressed combination of
results in the generation of BIOS function INT 1Bh. This software interrupt provides a method of
exiting an application and generally halts execution of the current program.
Technical Reference Guide
Pause
key (pos. 16), which produces a Make code only. All keys with the
Pause
and Easy Access keys are also typematic, although the typematic action
Caps Lock
key (pos. 59), when pressed and released, invokes a BIOS routine
Shift
key will reverse which state these keys are in based on the
Num Lock
key (pos. 32), when pressed and released, invokes a BIOS routine
Print Scrn
(pos. 14) key can, when pressed, generate an interrupt that initiates
Scroll Lock
key (pos. 15) when pressed and released, invokes a BIOS
Pause
(pos. 16) key, when pressed, can be used to cause the keyboard interrupt to
Insert Home
,
key (pos. 75/86), when held down, produces a shift state (upper case) for keys
Caps Lock
key is toggled on, then a held
keys (pos. 92/96) can be used in conjunction with keys in positions 1-13, 16,
Page Up Down, Delete
, /
Caps Lock
Shift
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Ins
, and keys is suppressed by
Caps Lock
End
, and keys operate at the
key (pos. 59) is
key produces the lower
Num Lock
Ctrl
Ctrl Break
and (pos. 16)
Keyboard
key.
state of
key
C-7