Tennis Cup 2 (cartridge)

Cover

Covers from CPCmania

• Tennis Cup 2
• 

  Back Cover

• 

  Front Cover

Cartridge

• Tennis Cup 2
• 

  Back Cartridge

• 

  Front 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 Support

This game is perhaps the only one on Amstrad GX4000/Plus range that supports an Analog Joystick, however, it converts the analog signals to digital signals by software. In two-player mode, the game can be controlled by:

• Digital Joystick #1 and Digital Joystick #2

or alternately (selectable in Options),

• Analog Joystick #1 and Digital Joystick #2

That feature is intended for people who own one digital stick, and one analogue stick (rather than two digital ones). In the "analog" mode, Digital Joystick #1 is not used (because it's button inputs would conflict with Analog Joystick #1).

Disassembly of the joystick code in Tennis Cup 2:

 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       ;keyb.row 9               ;\
 or      c                                     ;
 ld      b,0f6h                                ;
 out     (c),a                                 ; 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,261fh_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,2639h_DOWN      ;+14h..+20h         ;
 cp      0ech              ;-14h               ; read analog joystick 1,
 jp      p,263bh_Y_DONE    ;-14h..+13h         ; Y-axis (ADC1)
2634h_UP:                  ;-1Fh..-15h         ;
 set     0,c   ;bit0=up (as on digital joy)    ; convert to digital up/down
 jp      263bh_Y_DONE                          ;
2639h_DOWN:                                    ;
 set     1,c   ;bit1=down (as on digital joy)  ;
263bh_Y_DONE:                                  ;/
 ld      a,(8082h) ;joy1                       ;\
 and     10h       ;joy1 fire                  ; use digital joystick 1 fire
 or      c                                     ; as analog joystick 1 fire
 ld      (8085h),a ;store A/D converted analog ;/

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 )