My demoscene project completed

[blargg]

I started a new thread in general for hap's interesting topic.

[visy]

Another quick intro, this time featuring MMC3 and sampled technospeech

http://pouet.net/prod.php?which=26832

Also, and big scroller and some big bitmap mayhem. PAL.

[Memblers]

Nice. That's a lotta CHR.

[oRBIT2002]

That is so cool! However I can't seem to find an emulator that displays it properly (or is it coded to work on the hardware perhaps?)

[Disch]

My emu struggled with this MMC3 demo at first because of two issues:

1) The CHR size is wacky. $11 * 8k. I don't know if 136k CHR-ROM chips even exist? Why not bump it up to an even $20 * 8k and pad the end with 00's?

2) You assume PRG page 1 is swapped in at $A000. My emu wipes all mapper regs to $00 on powerup (putting page 0 at $A000)-- and your reset vector points somewhere to $Axxx which was causing it to crash after looping some weird DMC sample. Every commercial MMC3 game I've seen puts the Reset vector to $E000-FFFF for the reason that it's the only area which isn't swappable (ie: it will always be the last page of PRG).


Now I'm not saying the demo is wrong or bad. If it's working on the system then it works. Although I still think the practice of relying on the state of uninitialized mapper registers is somewhat "blech". Kind of like using RAM before you initialize it (only with potentially more severe consequences).


Anyway, after adjusting for those things the demo runs great. Very nice.

I still have a weird problem with the Quantum Disco Brothers demo you released. From what I can tell it runs right for the most part, except for the color bars part. A screenshot of how it looks in my emu:

http://disch.panicus.org/prob.png

I'm assuming that's supposed to be further down the screen and more centered. As it stands now there's a large black patch at the bottom for that whole portion of the demo. Is there a screenshot of how that's supposed to look?

[tepples]

1) The CHR size is wacky. $11 * 8k. I don't know if 136k CHR-ROM chips even exist? Why not bump it up to an even $20 * 8k and pad the end with 00's?

Because that appears to be the responsibility of the emulator. You'll notice that the common dumps of Smash TV and Tetris 2 also have undersize CHR.

2) You assume PRG page 1 is swapped in at $A000. My emu wipes all mapper regs to $00 on powerup (putting page 0 at $A000)-- and your reset vector points somewhere to $Axxx which was causing it to crash after looping some weird DMC sample. Every commercial MMC3 game I've seen puts the Reset vector to $E000-FFFF for the reason that it's the only area which isn't swappable (ie: it will always be the last page of PRG).

Then I guess someone needs to make an MMC3 test rom that checks the initial state of the MMC3 registers.

[85cocoa]

EDIT: Oops, removed first half of post - there's a different thread for that now...

I still have a weird problem with the Quantum Disco Brothers demo you released. From what I can tell it runs right for the most part, except for the color bars part. A screenshot of how it looks in my emu:

http://disch.panicus.org/prob.png

I'm assuming that's supposed to be further down the screen and more centered. As it stands now there's a large black patch at the bottom for that whole portion of the demo. Is there a screenshot of how that's supposed to look?

It looks pretty much the same as that in Nestopia and Nintendulator, so it's probably right.

[visy]

It looks pretty much the same as that in Nestopia and Nintendulator, so it's probably right.

Yeah, I ran out of time so that particular effect looks pretty lame.