mov ax, [Status] ; mouse motion and button status
mov bx, [deltaX] ; change in x
mov cx, [deltaY] ; change in y
mov dx, [ButtonCount] ; number of buttons
xor di,di ; DI must be zero
xor si,si ; SI must be zero
call [Mouse_Event] ; mouse-event function address
The Mouse_Event function records the mouse motion or button click. The mouse-interrupt handler calls this function when it has a new mouse event to report.
Status
Specifies whether the user moved the mouse, pressed a mouse button, or released a mouse button. The bits in this parameter can be a combination of the following values.
| Value | Meaning |
| SF_MOVEMENT (0001h) | Movement occured. |
| SF_B1_DOWN (0002h) | Button 1 (SW1) changed to down. |
| SF_B1_UP (0004h) | Button 1 (SW1) changed to up. |
| SF_B2_DOWN (0008h) | Button 2 (SW3) changed to down. |
| SF_B2_UP (0010h) | Button 2 (SW3) changed to up. |
| SF_ABSOLUTE (8000h) | The BX and CX registers contain normalized absolute coordinates. |
The bits specifying the button status are set to indicate a change in status on an ongoing condition. For example, if button 1 is pressed and held down, SF_B1_DOWN is set only when button 1 is first pressed but not for subsequent motions. Similarly, SF_B1_UP is set only when the button is first released.
deltaX
Specifies the amount of motion along the x-axis. This parameter is either the number of mickeys moved (for relative devices), or the actual x-coordinate (for absolute devices).
deltaY
Specifies the amount of motion along the y-axis. This parameter is either the number of mickeys moved (for relative devices), or the actual y-coordinate (for absolute devices).
ButtonCount
Specifies the number of buttons.
This function has no return value.
If there has been mouse motion (bit 0 of AX is set), the BX and CX registers hold the integer values of motion since the last mouse interrupt was generated for x and y, respectively.
If the SF_ABSOLUTE value is not specified in the Status parameter, the BX and CX registers specify relative motions from the last reported position. If this value is specified in Status, BX and CX contain normalized absolute coordinates between 0 and 65535, which will be mapped by the event procedure onto the display surface.
The DI and SI registers must be set to zero to ensure compatibility with Microsoft Windows for Pen Computing.