Int 2F Fn 1607  C - Ms Windows - "vmpoll" Virtual Device - Idle Callout    [W]

   AX = 1607h
   BX = 0018h (VMPoll VxD ID) (see #2329)
   CX = 0000h

Return: AX = status
       0000h if timeslice used
       nonzero if timeslice not needed

Note:  when VMPoll makes this callout, all virtual machines are idle, and any
     interested TSR can use the opportunity to perform background
     processing

See Also: AX=1607h"CALL OUT API",AX=1689h