Actraiser city map data is located at 0x50200 to 0x519FF. It's stored in 0x100 byte quadrants, four to a map, resulting in six 0x400 byte maps.
The quadrants are ordered as follows: top left, top right, bottom left, bottom right.
a...b g...h c...d i...j e...f k...l
m...n s...t o...p u...v q...r w...x
More map data appears to follow this data, to handle map changes caused by events (like the Marahna earthquake).
The overworld is one 128x128 map, located at 0x33541 to 0x37541. It doesn't make use of quadrants like the city maps do.
- A file concerning map data