Address Name Description
DFF1C8 VTOTAL Highest numbered vertical line (VERBEAMEN = 1)
DFF1CA VSSTOP Vertical position for VSYNC stop


It`s the line number to reset the counter, so there`s this many + 1
in a field. The exception is if the LACE bit is set (BPLCON0), in
which case every other field is this many + 2 and the short field
is this many + 1.

This material is most likely derived from the official Amiga documentation and where applicable copyright remains with the original author.