Changes

Retrieves the [[FF7/Field/Field ID|field ID]] number of the area field that was played directly before the current one, into the bank ''B'' and address ''A'' specified. If the The previous area was does not include the specific world map locations that are given a field but ID (0x1 to 0x40), so traversing via a gateway to the world map location, then back to the current field , will not cause the world map ID is to be retrieved instead; rather, that same field ID will be loaded.