Subject: Re: [stella] supercharger good; busted code bad From: "Eckhard Stolberg" <Eckhard_Stolberg@xxxxxx> Date: Sun, 14 Jul 2002 14:29:52 +0200 |
> One last mystery though... > my Sprites are refelcted opposite on the 2600 relative to > all 3 emus! the code below is 'correct' on the supercharged > atari, backwards everywhere else... I think Nicolás is right. You seem to have forgotten the # in front of your binary constants that you put into REFP0 and REFP1. One question though: are you by any chance using your Supercharger in an Atari 7800 console? The reason I'm asking is because if that were the case, it would explain the different behaviour between the emulators and your console. For the TIA read registers (which you are reading from, if you leave out the #) only the two topmost bits are defined. For the other six bits the programmers guide doesn't give a defined state. On a 2600 these bits will stay at whatever data has been on the data bus last. Since this usually is the address byte of the register, the results are the same for the lower six bits between reading $01 and reading #$01. On the 7800 Atari changed the state of the undefined bits. They now seem to always be zero. This is why your code fails on your Supercharger. > How foolish will I sound if I say "there's a dasm manual?" Yes there is. But I think it was only included with the DASM source code distribution. So you'd need to find a copy of that, if you want to have a look at the manual. Ciao, Eckhard Stolberg ---------------------------------------------------------------------------------------------- Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/
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