From SpecNext official Wiki
Number
|
$FADF
|
Decimal
|
64223
|
Short desc.
|
Reads buttons on Kempston Mouse.
|
Bit Mask
|
%---- ---0 --0- ----
|
Readable
|
Yes
|
Writable
|
No
|
Subsystem
|
Input
|
Bit |
Function
|
7-4 |
contains wheel-delta value (0..15) since previous read.
|
3 |
fourth button
|
2 |
middle button
|
1 |
left button
|
0 |
right button
|