Changes

==Analog JoystickSupport ==

This games game is pehaps perhaps the only one on Amstrad GX4000/Plus range to enable the use of that supports an [[Analog Joysticks| Analog Joystick]], for however, it converts the 2nd playeranalog signals to digital signals by software.  ld bcIn two-player mode,0f40ehthe game can be controlled by: out (c),c ld b,0f6h in a,(c) * Digital Joystick #1 and 30hDigital Joystick #2 ld c,a or 0c0h out alternately (cselectable in Options),a out (c),c* Analog Joystick #1 and Digital Joystick #2 inc b ld a,92h out (c),a push bc set 6,c ld a,09h ;; keyboard line That feature is intended for joy 0 or c ld bpeople who own one digital stick,0f6h out and one analogue stick (crather than two digital ones). In the "analog" mode,a ld b,0f4h in a,(c) cpl ld (8082h),a ;; joy 0 push af ld a,06h ;; keyboard line for joy Digital Joystick #1 or c ld b,0f6h out is not used (c),a ld b,0f4h in a,(c) cpl ld (8083h),a ;; joy because its button inputs would conflict with Analog Joystick #1 pop de or d ld (8086h),a ld a,03h or c ld b,0f6h out (c),a ld b,0f4h in a,(c) cpl ld (8084h),a ;; pause? pop bc ld a,82h out (c),a dec b out (c),c ld bc,7fb8h out (c),c.

ld c,00h ld a,(6808h) ;; analogue input channel 0 sub 1fh cp 14h jp p,261fh cp 0ech jp m,2623h jr 2625h 261f set 3,c ;; right jr 2625h 2623 set Disassembly of the joystick code in Tennis Cup 2,c ;; left:

2625 ld bc,0f40eh out (c),c ld b,0f6h in a,(6809hc) and 30h ld c,a or 0c0h out (c),a out (c),c inc b ld a,92h out (c),a push bc set 6,c ld a,09h ;keyb.row 9 ;\ or c ; ld b,0f6h ; out (c),a ; analogue input channel read digital joystick 1 ld b,0f4h ; in a,(c) ; cpl ; ld (8082h),a ;store joy 1 ;/ push af ;push joy 1 ld a,06h ;keyb.row6 ;\ or c ; ld b,0f6h ; out (c),a ; read digital joystick 2 ld b,0f4h ; in a,(c) ; cpl ; ld (8083h),a ;store joy 2 ;/ pop de ;pop joy 1 ;\ or d ;merge joy 2 ; merge digital joystick 1+2 ld (8086h),a ;store both ;/ ld a,03h ;keyb.row3 ;\ or c ; read pause button ld b,0f6h ; (aka "P" key) out (c),a ; (row3.bit3) ld b,0f4h ; (bit3 still needs to be in a,(c) ; isolated elsewhere) cpl ; ld (8084h),a ;store pause ;/ pop bc ld a,82h out (c),a dec b out (c),c ld bc,7fb8h out (c),c ld c,00h ;digital-joystick-style bits ld a,(6808h) ;ADC0 ;+00h..+3Fh ;\ sub 1fh ;-1Fh..+20h ; cp 14h ; jp p,2639h261fh_RIGHT ;+14h..+20h ; cp 0ech ;-14h ; read analog joystick 1, jp m,2623h_LEFT ;-1Fh..-15h ; X-axis (ADC0) jr 2625h_X_DONE ;-14h..+13h ; 261f_RIGHT: ; set 3,c ;bit3=right (as on digital joy) ; convert to digital left/right jr 2625h_X_DONE ; 2623_LEFT: ; set 2,c ;bit2=left (as on digital joy) ; 2625_X_DONE: ;/ ld a,(6809h) ;ADC0 ;+00h..+3Fh ;\ sub 1fh ;-1Fh..+20h ; cp 14h ; jp p,263bh2639h_DOWN ;+14h..+20h ; cp 0ech ;-14h ; read analog joystick 1, jp p,263bh_Y_DONE ;-14h..+13h ; Y-axis (ADC1) 2634 2634h_UP: ;-1Fh..-15h ; set 0,c ;bit0=up (as on digital joy) ; convert to digital up /down jp 263bh263bh_Y_DONE ; 2639 2639h_DOWN: ; set 1,c ; ; bit1=down(as on digital joy) ; 263b 263bh_Y_DONE: ;/ ld a,(8082h) ;joy1 ; joy 0 fire.\ and 10h ;joy1 fire ; use digital joystick 1 fire or c ; as analog joystick 1 fire ld (8085h),a;store A/D converted analog ;/