PLAYER START subroutine: Difference between revisions
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The PLAYER_START subroutine is called by the [[ | The PLAYER_START subroutine is called by the [[System ROM]] if one of the start buttons are pressed while the corresponding player has enough credits or when the time runs out while the game's title is being displayed (?). | ||
BIOS_START_FLAG ($10FDB4.b) indicates which player pushed start (active high): | BIOS_START_FLAG ($10FDB4.b) indicates which player pushed start (active high): | ||
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*10FDB9.b for P4 | *10FDB9.b for P4 | ||
After returning, the | After returning, the System ROM deducts credits according to BIOS_START_FLAG. | ||
[[Category:Code]] | [[Category:Code]] | ||
Revision as of 06:35, 28 October 2015
The PLAYER_START subroutine is called by the System ROM if one of the start buttons are pressed while the corresponding player has enough credits or when the time runs out while the game's title is being displayed (?).
BIOS_START_FLAG ($10FDB4.b) indicates which player pushed start (active high):
This subroutine needs to leave these bits to "1" if the game can be started, or clear them if not. When the game is started, it has to set to "1" the corresponding bytes for each player:- 10FDB6.b for P1
- 10FDB7.b for P2
- 10FDB8.b for P3
- 10FDB9.b for P4