SlotVInstall
SlotVInstall Install vertical retrace interrupt task for a slot
#include <Retrace.h> Vert. Retrace Mgr
OSErr SlotVInstall(vblTaskPtr , theSlot);
QElemPtr vblTaskPtr ; address of a 14-byte VBLTask structure
short theSlot; slot whose queue the task should be installed in
returns 16-bit Error Code; 0=no error
SlotVInstall sets up to perform a task periodically. It installs an element
into the vertical retrace task queue of a particular slot. The task will be
executed whenever that device's vertical retrace interrupt occurs.
vblTaskPtr is the address of a 14-byte VBLTask structure. You must initialize
the fields of the structure before making the call.
theSlot is the slot number of the slot whose queue the task should be
installed in. You can use the Slot Manager routine SGetSRsrc to
index through all the slots on a particular machine.
Returns: an error return code indicating success or failure of the function. It
will be one of:
noErr (0) No error
vTypErr (-2) Invalid queue element
slotNumErr (-360) Invalid slot number

Notes: Instead of maintaining a single vertical retrace queue, the
Vertical Retrace Manager maintains a separate queue for each video
device; associated with that queue is the rate at which the device's vertical
retrace interrupt occurs. When interrupts occur for a particular video
slot, the Vertical Retrace Manager executes any tasks in the queue for
that slot.
See VInstall for more information on writing tasks that need to execute
periodically and a code example which demonstrates the installation of a VBL
Task.