SYSTEM IO: Difference between revisions

Latest revision as of 12:02, 15 April 2018

Should be called at the end of the VBlank interrupt routine.

Reads coin and game select inputs, jumps to COIN_SOUND, PLAYER_START or DEMO_END accordingly.

Reads the player inputs and sets values in RAM accordingly, see BIOS_RAM_locations#Joypad_Related.

This call does NOT save registers.

@@ Line 1: / Line 1: @@
-==BIOSF_SYSTEM_IO ($C0044A)==
+==SYSTEM_IO ($C0044A)==
 Should be called at the end of the [[68k interrupts|VBlank]] interrupt routine.
-Reads coin and game select inputs, jumps to COIN_SOUND, PLAYER_START or DEMO_END accordingly.
+Reads coin and game select inputs, jumps to [[COIN SOUND subroutine|COIN_SOUND]], [[PLAYER START subroutine|PLAYER_START]] or [[DEMO END subroutine|DEMO_END]] accordingly.
-Reads the player inputs and sets values in [[68k user RAM|RAM]] accordingly:
+Reads the player inputs and sets values in [[68k user RAM|RAM]] accordingly, see [[BIOS_RAM_locations#Joypad_Related]].
-;BIOS_P1STATUS ($10FD94):
+'''This call does NOT save registers.'''
-:0:No joypad connected
-:1:Normal joypad
-:2:Expanded joypad (?)
-:3:Mahjong controler
-:4:Keyboard
-;BIOS_P1CURRENT ($10FD95) inverted with P1_PREVIOUS ?
-;BIOS_P1PREVIOUS ($10FD96)
-;BIOS_P1CHANGE ($10FD97) rising edge detection (OFF to ON)
-;BIOS_P1REPEAT ($10FD98) rising edge detection + repeat each 8th frame after 16 frames
-;BIOS_P1TIMER ($10FD99) repeat timer (used ?)
-;BIOS_P2STATUS ($10FD9A)
-;BIOS_P2CURRENT ($10FD9B)
-;BIOS_P2PREVIOUS ($10FD9C)
-;BIOS_P2CHANGE ($10FD9D)
-;BIOS_P2REPEAT ($10FD9E)
-;BIOS_P2TIMER ($10FD99)
-All bits are active high.
 [[Category:BIOS calls]]