Re: A82: Blockbuster bug

To: assembly-82@lists.ticalc.org
Subject: Re: A82: Blockbuster bug
From: "Evil Sam" <evil_sam@hotmail.com>
Date: Sun, 01 Nov 1998 13:55:01 PST
Delivered-To: assembly-82-outgoing@towerguard.unix.edu.sollentuna.se
Reply-To: assembly-82@lists.ticalc.org


>Hi.  I wrote Blockbuster, originally for Ash, but it also worked fine 
>under CrASH v1.1.  Recently, however, it has caused other games to 
crash 
>when I use later versions of CrASH.  It always crashes ZTetris whenever 
>I run Blockbuster first.  All I have to do is run the title screen of 
>Blockbuster, too, I don't have to even play the game, and it crashes 
>ZTetris immediately.  However, if I used the teacher key and saved a 
>ZTetris game, it will run fine if I restore that game after running 
>Blockbuster, and then crash when I exit.
>
>Interestingly, when I run Columns v3.0c (even just the title screen) 
>between Blockbuster and ZTetris, nothing crashes, but since there's no 
>source available, I can't find out why.
>
>Here's the source to the title screen of Blockbuster.  I can't figure 
>out what it's doing wrong.  Perhaps someone more experienced can.
>
>Beginning:
>	ROM_CALL(CLEARLCD)
>	set 1,(IY+05)
>	set 3,(IY+05)

>
>Choose:
>	call GET_KEY
>	cp $01
>	jr z,DownOrUpKeyIsPressed
>	cp $04
>	jr z,DownOrUpKeyIsPressed
>	cp $09
>	jr z,EnterIsPressed
>	cp $37
>	ret z


  Ooh! Bug fixing, something I'm good at along with optimizing.

   Ok, the problem is in these 2 places above. You set 1,(iy+05) in the 
beginning, but when you exit you don't "res" it. Without the res 
1,(iy+05), I think it messes up the Ztetris menu system explaining why 
if Ztetris saved a game then it works phenomena(can't spell today). 
  And that's your problem! What does set 1,(iy+05) do exactly? 
Obviously, it has something to with text display.

   Sam

______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com