So I tried to make a game and this happened

[JRBasic]

So I tried to make a game, but when I tested movement, the character was stuck in place!
Here's the code, It's in CBM prg Studio

Code: Select all

*=$1800 ; starting location is $1800
init
        lda #$0A ; load char J
        sta $1400 ; store into $1400 for later use
        ldx #$00 ; load position
        lda #$93
        jsr $ffd2 ; clean the screen before continuing
start ; done intializing
        lda $1400
        sta $1E00,x ; store into position
        lda #$06
        sta 38400,x ; store blue into color ram
        lda $00C5 ; load value of C5 (keyboard matrix)
        cmp 18 ; compare with 18 (d key)
        beq moveright ; if d is pressed, move right 1 tile
        bne start ; if no key pressed, go back to start label
loop
        jmp loop ; just lock the vic-20
moveright
        inx ; increment x
        lda #$93
        jsr $ffd2 ; and clean the screen so no trail is present
        lda $1400 ; load player character
        sta $1E00,x ; redraw it
        jmp start ; and then return to start lab

[srowe]

Your CMP instruction is using a zero page address rather than an immediate value.

[JRBasic]

Didn't think that would work, but thanks!
Moves really fast, though, how do I check if the key is pressed, rather than being held down?

[20questions]

Didn't think that would work, but thanks!
Moves really fast, though, how do I check if the key is pressed, rather than being held down?

try inkey$, if possible or get a$

[retrojello]

Didn't think that would work, but thanks!
Moves really fast, though, how do I check if the key is pressed, rather than being held down?

try inkey$, if possible or get a$

20questions=idiot

[20questions]

Didn't think that would work, but thanks!
Moves really fast, though, how do I check if the key is pressed, rather than being held down?

try inkey$, if possible or get a$

20questions=idiot

what the hell was that for? i'm trying to help.

[Mike]

what the hell was that for? i'm trying to help.

To put things into perspective: first, you were replying to a question that was already half a year old. Either JRBasic found an answer by himself and just didn't bother to communicate that, or your 'help' was much too late anyhow. Second, your reply referenced a non-existing command (there's no "inkey$" in BASIC V2), but "get a$" (or better, its ML equivalent CHRIN) is probably even the correct answer - by sheer luck.

Main concern about JRBasic's question was: the program "sees" the keys "continuously" pressed when probing address 197, whereas he probably only wanted to move the character once upon the change non-pressed->pressed. Other than using the KERNAL CHRIN call for this, that kind of problem is usually solved by keeping the previous state to indicate whether there was a change, and only then do the desired action.

[orion70]

Nothing justifies insulting anyone here. I invite members to avoid name calling.

[20questions]

what the hell was that for? i'm trying to help.

To put things into perspective: first, you were replying to a question that was already half a year old. Either JRBasic found an answer by himself and just didn't bother to communicate that, or your 'help' was much too late anyhow. Second, your reply referenced a non-existing command (there's no "inkey$" in BASIC V2), but "get a$" (or better, its ML equivalent CHRIN) is probably even the correct answer - by sheer luck.

Main concern about JRBasic's question was: the program "sees" the keys "continuously" pressed when probing address 197, whereas he probably only wanted to move the character once upon the change non-pressed->pressed. Other than using the KERNAL CHRIN call for this, that kind of problem is usually solved by keeping the previous state to indicate whether there was a change, and only then do the desired action.

that doesn't justify him calling me an idiot. this is why i rarely help anyone on forums. people are just to unpredictable online.

[joshuadenmark]

We will not tolerate this at all.

retrojello=deleted

[pixel]

We will not tolerate this at all.

retrojello=deleted

Thank you!