Legacy Document

Inside Macintosh: Processes

Chapter 4 - Vertical Retrace Manager / Vertical Retrace Manager Reference

Vertical Retrace Manager Routines / Slot-Based Installation and Removal Routines

SlotVRemove

You can use the SlotVRemove function to remove a task record from a slot-based vertical retrace queue.

FUNCTION SlotVRemove (vblTaskPtr: QElemPtr; theSlot: Integer): 
                      OSErr;

vblTaskPtr

A pointer to the task record to remove from its queue.

theSlot

The slot number of the video device from whose vertical retrace queue the task record is removed.

DESCRIPTION

The SlotVRemove function removes the task record specified by the vblTaskPtr parameter from the vertical retrace queue associated with the video device specified by the theSlot parameter.

To disable a slot-based VBL task temporarily, you can set the vblCount field of the task record to 0.

ASSEMBLY-LANGUAGE INFORMATION

The registers on entry and exit for SlotVRemove are

Registers on entry
A0	Pointer to the task record
D0	Slot number of the device associated with the vertical retrace queue

Registers on exit
D0	Result code

RESULT CODES

noErr	0	No error
qErr	-1	Task record isn't in the queue
vTypErr	-2	Invalid qType value (must be ORD(vType))
slotNumErr	-360	Invalid slot number