Basic Questions and Answers Thread

In the code, everything related to enemy things are in (a1), example, this line:

Code:

sub.w	$C(a1),d1; substract enemy's Y-position from it

I did this:

Code:

jmp   Touch_KillEnemy

But this doesn't clear my problems. Please, help me out :|

 

hopefully some can help me out here, but recently I have been trying to figure out were to find the super peel-out SFX as well as the SPO release SFX within the ISO file for sonic CD and make a genesis port of it but the only thing is that I don't know were to find them. I was wondering how anyone else was able to do it and maybe help me out on this.

 

Isin't it the simple spindash release sound effect? I don't know where to find them, but why don't you use your existing sound effects? That is what I did. I guess just do a search for an SMPS header and look if the SFX looks like it, and then port it.

 

I also need help with the spike blast thingy.

 

I have two questions, one is about the music, and isn't really important, the second is about the flickering.


-1


I read that, in S1, only the special stage music had 6 channels, which I translated in my head into "the other musics have less channels" (correct me if I'm wrong). So, would it be possible to add a channel that would play only under some circumstances? When Sonic is invincible for example.


Or maybe it's been done/tried before?


It's really no more than an idea I've had several times, especially when I was playing with super Sonic in S2 and S3. I'd only like to know if it's possible to send such requests to the sound driver/processor.


-2


Does someone know what exactly causes the flickering when there are too many things on screen: is it the number of objects, the number of sprites, the number of pieces or the number of tiles (using the terms of sonmaped)?


I don't really think it's related to the number of objects (though I may be wrong), which is more likely to cause slowdowns. If it's related to the sprites, it could be difficult to fix it, but working on the animations could help. If it's the number of pieces, optimizing the sprites with smaller pieces could be counterproductive, and if it's the number of tiles, redrawing some sprites and animations could help.

 

@Question 2: It's the number of sprites. The Sega Genesis can't display more than 80 different sprites at the same time. You can see that best with the Debug Mode, where the Time is being replaced with a counter, that counts all sprites on the screen. It will NEVER go past 80.

 

Any of the other tracks can use up to 6 FM channels, of course at the cost of the 6th channel, you can use the DAC channel for PCM samples, so yeah, it is possible to use all 6 FM channels for any track, but by doing so you won't be able to use the DAC channel.


In order to set this, opening the music tracks with a hex editor, you'll notice the 3rd byte if using the DAC and 5 FM channels, will be set to a 06, if all 6 FM channels are used but no DAC channel, it'll be set to 07. Of course, the header will be adjusted for an extra FM 6 entry, and the DAC channel will automatically be set to run the F2 flag (Stop Flag).


The sprites glitch due to either:


(A.) The maximum number of sprites have elapsed (80 Dem/50 Hex).


(B.) Too many sprites lined up horizontally results in the mask effect.

 

Thanks, it might be difficult, but knowing that I should be able to find a way to avoid or reduce the problem with sprites and keep the original look.


About the music, it looks like I'll have to find another way, removing the DAC channel doesn't sound like a good option.

 

What format are the 16x16 tiles in Sonic 1 & Sonic 2?


Trying to get S1's 16x16s to load in S2 as an experiment.

 

The map code formats are the same, unless you mean compression formats which are different, Sonic 1 uses Enigma for compression while Sonic 2 uses Kosinski for compression.

 

Okay, next question. Any differences in the Collision formats/compression for these? I'm having a little more difficulty in this aspect... Copying over collision files from S1 - S2 seems to make no difference, but causes no errors, so I'm baffled. =P

 

The collision for Sonic 1 and Sonic 2 are the same, except Sonic 2 has a second collision set for the path swapping system, the only difference is (again) compression, while Sonic 1's is uncompressed, Sonic 2's is Kosinski compressed.


Would it help if I provided a link to Project Sonic 1:Two-Eight where all the data is pre-converted and the engine on the Sonic 1 disassembly runs Sonic 2's format? =P


http://sonicresearch.org/forums/index.php?showtopic=2141

 

Thought it'd help, still having absolutely no progress in porting the collision... I can't figure it out. Well, I suppose I'll have to give it another go tomorrow. =P

 

Have you tried porting the "Collision Array" itself, rather than the Zone's individual collision files? Sonic 1 and Sonic 2 have different collision array data. (Also not to forget the "Collision Rotate" data)


Try looking up these files (2007 Hivebrain):


collide\anglemap.bin


collide\carray_n.bin


collide\carray_r.bin


If that's not it, then I'm not sure whatelse, sorry.

 

Got the Sonic 1: Two Eight versions of those copied over.


Got the array files, and the zone files, but still no luck.

 

People, i have a few questions.


1.- I've been looking at free art locations, but unlucky I didn't find any. I want to know some art locations, because I'm having problems with the lamp post (Not related to the spindash thingy), but i added art for a monitor, but the lamp post has part of that art.


2.- I made a miniboss for GHZ in a friend's hack (Which is the real GHZ boss). But unlucky, when you destroy the boss, the ball doesn't explode and stays where it was before. I tried all i could for that. Could you please give suggestions on how to fix it?


If you ask, those questions are related to Sonic The Hedgehog 1 hacking.


Thanks from advance!


-DeoxysKyogre

 

http://sonicresearch.org/tables?vram.html


That should answer your question.

 

For the first question, considering all addresses are being used at least once in the game, you could either modify the lamp post (you should be able to free 2 tiles easily by making the thin part 1x2 rather than 2x2), or modify its art (that could save a third tile). Another option is to remove some of the static animation frames, or free some vram using DPLCs. Last option I can think of right now would be to make art addresses depending on the current zone.


For the second question, you could change the ball's routine counter from the boss' code. Not sure what's wrong with it though, so it may not work either.

 

Okay, i'm trying to setup the Sonic 2 Dissasembly, but I need the Sonic 2 REV01 ROM.


I searched on Sonic Retro, but the assembly page seems to have disappeared.


Can anyone provide a link, or ask QJimbo for assistance? I'm following his guide after all.


I'll keep looking for that file.

 

You can find the ROM here