This games is pehaps the only one on Amstrad GX4000/Plus range to enable the use of an [[Analog Joysticks| Analog Joystick]], for the 2nd player.
* Player 1 can use Digital Joystick #1
* Player 2 can use Digital Joystick #2, or alternately, Analog Joystick #1
The game converts the analog inputs to digital-joystick-style "on/off" signals, so it isn't actually supporting "fast/slow" analog inputs.
ld bc,0f40eh out (c),c ld b,0f6h in a,(c) 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 ;; keyboard line for joy 0 or c ld b,0f6h out (c),a ld b,0f4h in a,(c) cpl ld (8082h),a ;; joy 0 push af ld a,06h ;; keyboard line for joy 1 or c ld b,0f6h out (c),a ld b,0f4h in a,(c) cpl ld (8083h),a ;; joy 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 2,c ;; left 2625 : ld a,(6809h) ;; analogue input channel 1 sub 1fh cp 14h jp p,2639h cp 0ech jp p,263bh 2634 : set 0,c ;; up jp 263bh 2639 : set 1,c ;; down 263b : ld a,(8082h) ;; joy 0 fire. and 10h or c ld (8085h),a
The keyboard is read to determine the state of the digital joysticks and the P button (pause button on gx4000 console).
