PLAYER START subroutine: Difference between revisions
Jump to navigation
Jump to search
m (Created page with "The PLAYER_START subroutine is called 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 i...") |
mNo edit summary |
||
| Line 1: | Line 1: | ||
The PLAYER_START subroutine is called 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 displayed. | The PLAYER_START subroutine is called by the [[BIOSes|BIOS]] 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): | |||
{|8BitRegister|.|4|P4|1|P3|1|P2|1|P1|1|} | {|8BitRegister|.|4|P4|1|P3|1|P2|1|P1|1|} | ||
| Line 12: | Line 12: | ||
*10FDB8.b for P3 | *10FDB8.b for P3 | ||
*10FDB9.b for P4 | *10FDB9.b for P4 | ||
After returning, the BIOS deducts credits according to BIOS_START_FLAG. | |||
[[Category:Code]] | [[Category:Code]] | ||
Revision as of 12:19, 8 October 2011
The PLAYER_START subroutine is called by the BIOS 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