HP dc71xx Manuale Utente

All keys generate a Make code (when pressed) and a Break code (when released) with the 
exception of the 

 key (pos. 16), which produces a Make code only. All keys with the 

exception of the 

 and Easy Access keys are also typematic, although the typematic action 

of the 

, and 

 keys is suppressed by 

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. 

The following keys provide the intended function in most applications and environments.

—The 

 key (pos. 59), when pressed and released, invokes a BIOS routine 

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 

 key will reverse which state these keys are in based on the 

 key.

—The 

 key (pos. 32), when pressed and released, invokes a BIOS routine 

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. 

—The 

 (pos. 14) key can, when pressed, generate an interrupt that initiates 

a print routine.  This function may be inhibited by the application. 

—The 

 key (pos. 15) when pressed and released, invokes a BIOS 

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.

—The 

 (pos. 16) key, when pressed, can be used to cause the keyboard interrupt to 

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.

The 

, 

 (function), 

, 

, 

/

, and 

 keys operate at the 

discretion of the application software.

—The 

 key (pos. 75/86), when held down, produces a shift state (upper case) for keys 

in positions 17-29, 30, 39-51, 60-70, and 76-85 as long as the 

 key (pos. 59) is 

toggled off. If the 

 key is toggled on, then a held 

 key produces the lower 

(normal) case for the identified pressed keys. The Shift key also reverses the 

 state of 

key positions  55-57, 72, 74, 88-90, 100, and 101. 

—The 

 keys (pos. 92/96) can be used in conjunction with keys in positions 1-13, 16, 

17-34, 39-54, 60-71, and 76-84. The application determines the actual function. Both 

 key 

positions provide identical functionality. The pressed combination of 

 and 

 (pos. 16) 

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.