Re: [stella] Adventure, Another Issue (Thanks for yesterday)

Subject: Re: [stella] Adventure, Another Issue (Thanks for yesterday)
From: "Joel Park" <joelp@xxxxxxxxxxxxxxxxxx>
Date: Tue, 4 Jun 2002 08:59:43 -0400

Thanks for the fast reply.
And for the huge help, I'll try this stuff out tonight.

What you were mentioning about PageBreaks...  As long as I keep all the room
data within one "High" range I should be ok right??  Like as long as it's
between FE00 and FEFF I shoud be fine, right.  (Sorry for such a newbie

Thanks to all you guys,  I really appreciate how helpful everyone is.

----- Original Message -----
From: "Brian Prescott" <bprescot@xxxxxxxxxxxxxxx>
To: <stella@xxxxxxxxxxx>
Sent: Tuesday, June 04, 2002 8:39 AM
Subject: RE: [stella] Adventure, Another Issue (Thanks for yesterday)

> Joel:
> The problem is in the RoomNumToAddress subroutine.  This routine
> an address into the room data table.  By adding a byte to the arrow
> these addresses are all off by one.
> In the subroutine, you can change the final bit of code to this:
>        LDA    #<RoomDataTable
>        CLC
>        ADC    $93                 ;Add the room data base address
>        STA    $93                 ;to the offset therefore getting
>        LDA    #>RoomDataTable                ;      the final room data
> address.
>        ADC    $94
>        STA    $94
>        RTS
> And of course, add the RoomDataTable label at FE1B.
> When you do this kind of thing in the actual code instead of the table
> at the end, you also need to be aware that page breaks can and do cause
> code to go haywire.  I found this out in some of my own disassemblies and
> code modifications.
> BP
> -----Original Message-----
> From: owner-stella@xxxxxxxxxxx [mailto:owner-stella@xxxxxxxxxxx]On
> Behalf Of Joel Park
> Sent: Tuesday, June 04, 2002 8:04 AM
> To: stella@xxxxxxxxxxx
> Subject: [stella] Adventure, Another Issue (Thanks for yesterday)
> Once I got a newer version of DASM, I was all ready to go and everything
> worked great and I thought I had all the labels added, But...
> It still looks to be accessing memory directly somewhere instead of using
> labels but for the life of me I can't find it.. I've been through the code
> multiple times,  line per line and can't find any place that would be
> me problems.
> Here is what I do to test.
> I went to the graphic for the Sword and added an extra line of graphics in
> the middle, to make it higher.   Then I go clear to the end and there are
> like 9 bytes that are labeled as "Unused", I remove one of them to keep my
> program 4K.
> When I compile and run,  the whole game is freaking out..  The issue seems
> to be related to the dynamic backgrounds and not my sprites because they
> look fine and any changes I make to them are visible.. But the background
> are pretty much all gone and it's just a garbled mess nearly impossible to
> navigate.
> The version of the code I attached has all the lables and everything and
> still compiles.  Could someone check it out and see if I missed something
> when adding lables or something..  There may be an assembler command that
> setting the high byte of my memory addresses and I'm just not picking it
> or something.
> Thanks,
> Joel D. Park
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