Stage one VBLANK calculations entry. It performs the processing of a VBLANK interrupt. Contains JMP instruction for the vector in the next two addresses (58464, 58465; $E460, $E461). This is the address normally found in VVBLKI (546, 547; $222, $223). It is initialized to 59345 ($E7D1), which is the VBLANK routine entry. Initialized to 59345 ($E7D1) old ROMs, 59310 ($E7AE) new ROMs.

see also: VDSLST, VVBLKI, VVBLKD, Interrupt