X"B0" function 2
Tests the status of the Shift, Alt, Ctrl and Lock keys.
Syntax:
call X"B0" using function-code
status-block
Parameters:
|
Using call prototype (see
Library Routines - Key) |
Picture (32-bit systems) |
function-code |
cblt-x1-compx |
pic x comp-x. |
status-block |
Group containing: |
Group containing: |
|
status-inds |
|
pic x |
|
pic x |
|
status-id |
|
cblt-x1-compx |
|
pic x comp-x. |
|
status-res |
|
pic x(6) |
|
pic x(6) |
On Entry:
function-code |
Value 2. |
status-id |
Must be set to 2. It is overwritten by the call, so must be
reset to 2 before each call. |
status-res |
Reserved. |
On Exit:
status-inds |
Contains bit settings indicating the status of the keys (1=key
pressed, 0=key not pressed) in the following order:
bit 7 |
Ins |
bit 6 |
Caps Lock |
bit 5 |
Num Lock |
bit 4 |
Scroll Lock |
bit 3 |
Alt |
bit 2 |
Ctrl |
bit 1 |
Shift (left key only) |
bit 0 |
Shift (right key only) |
|
Comments:
For the Alt, Ctrl and Shift keys, the routine returns a 1 only if
the key is actually pressed when the routine is called; for the other keys, the
relevant bit is alternately set and unset each time the key is pressed.
Effective use of function 2 requires that the call is repeated at
very frequent intervals.
Keyboard Routines - Example
See Also: