Re: LZ: variables


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Re: LZ: variables



Will Stokes (3D Diamond productions) wrote:
> 
>                                    wstokes@vertex.ucls.uchicago.edu
>                                    http://www.uic.edu/~hhstokes/index.html
>                                    Will Stokes
>         to all of the people out there who responded to my earlier
> question, thankyou, I got one of the solutions to work. Now  I have a
> rather simple questions having to do with keystrokes: here's my code:
> 
> Top:
>         CALL_(Get)              ;in the basic stem of program
>                                 ; 'Get' is called
> 
> Get:                                    ;a subrotine i made
>         call GET_KEY                    ;get the last keystoke
>         cp $37                          ; was exit presses
>         ret z                           ; if so exit to zshell menu
>         cp $02                          ; was left arrow pressed
>         CALL_(Left)                     ; ok run 'Left'
>         cp $03                          ; was right pressed
>         CALL_(Right)                    ; ok run 'Right'
>         JUMP_(Top)                      ; go back to 'Top'
> Left:
>         dec a                           ;a=a-1
>         cp 0                            ;compare a to zero
>         jr z, L2                        ; if zerso jumpto 'L2'
>         ret                             ; if not it will return to 'Get'
> L2:
>         ld a, 9                         ; a=9
>         ret
> Right:
>         inc a
>         cp 10
>         jr z, R2
>         ret
> R2:
>         ld a, 1
>         ret
> -----------------------------------------------------------
> the exit to zshell part works but the left and right commands don't for
> some reason, is there somthing visible here that I'm doing wrong????


As many people have said, you must CALL_Z instead of CALL_. Another thing is that it's not so 
clever to JUMP_(Top). After a while the stack will get overflowed (= the calc will probably 
crash). You must RET back to the top.


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References: