Cover
Cartridge
Manual
You can download in PDF from CPCmania ( See the links ).
Game
You can download in CPR for use in emulators and BIN from CPCmania ( See the links ).
Analog Joystick
This games is pehaps the only one on Amstrad GX4000/Plus range to enable the use of an Analog Joystick, for the 2nd player.
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
260c 0e00 ld c,00h 260e 3a0868 ld a,(6808h) ;; analogue input channel 0 2611 d61f sub 1fh 2613 fe14 cp 14h 2615 f21f26 jp p,261fh 2618 feec cp 0ech 261a fa2326 jp m,2623h 261d 1806 jr 2625h
261f cbd9 set 3,c ;; right 2621 1802 jr 2625h
2623 cbd1 set 2,c ;; left
2625 3a0968 ld a,(6809h) ;; analogue input channel 1 2628 d61f sub 1fh 262a fe14 cp 14h 262c f23926 jp p,2639h 262f feec cp 0ech 2631 f23b26 jp p,263bh 2634 cbc1 set 0,c ;; up 2636 c33b26 jp 263bh 2639 cbc9 set 1,c ;; down
263b 3a8280 ld a,(8082h) ;; joy 0 fire. 263e e610 and 10h 2640 b1 or c 2641 328580 ld (8085h),a
The keyboard is read to determine the state of the digital joysticks and the P button (pause button on gx4000 console).
The routine reads analogue input channel 0 and 1 for the analogue joystick and performs some checking to see the range of the numbers. Based on this it sets the direction pressed.
Links
http://www.cpcmania.com/ ( on the games section : GX4000/CPC+ GAMES )