Project Sonic 1: Two-Eight

I was gonna keep this quiet for a while but to be frank, I just can't be bothered holding something that may be useful for public eyes (No really, I'm terrible for releasing work of my own earlier than planned).

There have been conversations before now about the difference between hacking Sonic 1 and Sonic 2 and which one would be the best to go for, almost everyone will agree that Sonic 2 is the best to hack as the software features a set load of engines that have been improved since Sonic 1's release, though I couldn't get my head around the idea of a 128x128 chunk and path-swapper system somehow being better because of it's flexibility, although I do agree, I find that a lot of levels made out of this system tend to only be better depending on how they're used (Yeah, obvious I know).

But rather than spend ages moaning about it, I decided to do the next best thing, put Sonic 1 into the same situation as Sonic 2.

Download this.

The link above is a disassembly of Sonic The Hedgehog (16-bit), but it is no ordinary disassembly, it has been modified to run 128x128 chunks and the path-swapper system whilst keeping everything else more or less intact, which I'm releasing publicly in the hope that some may be encouraged to work on Sonic 1 with this system, and possibly do things with Sonic 1's layout which may seem to have been impossible via the 256x256 system.

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A few notes, I won't be providing any guides on how to port/make the 128x128 system work on Sonic 1, if you wish to understand the changes involved, simply search “; MJ:” in the source code, I have commented pretty much all of the coding that was done to enable the 128x128 system. Special chunks (S-Bends, Water slides, etc), these are done in pretty much the same way as the original 256x256 system was done, but altered to work with the 128 chunks, the wall change in LZ Act 3 which happens upon pressing a switch/button, had to be done differently as the layouts are no longer loaded into ram, but is still functional. The loops however, are done by the simple Path-Swapper object system as seen in Sonic 2.

Using SonED 2. The disassembly will not contain any copy of SonED, you'll have to obtain/download this yourself, the disassembly does contain sep files though, which are setup ready to be used with SonED 2 for editing the levels, unfortunately, SonED 2 will think that you are editing Sonic 2, and although it was able to read the Sonic 1 object list, the object system itself will still be based on that of Sonic 2. What you'll need to be careful of is setting “Remember Sprite” and placing Rings, placing rings must be done by the double left click method and selecting from the list, attempting to double right click the rings in, will add the rings to a ring position file which doesn't exist and will not be read by Sonic 1. “Remember Sprite” must be set by increasing the Object's ID by +80, not by pressing the “0” key on your keyboard.

As for porting levels from your pre-made Sonic 1 hacks (if you intend to), inside the disassembly there is a Converter in directory “SONED2S2DATA\Converter”, I've written to convert and optimise the 256 chunks, FG layouts and BG Layouts, of course there are probably plenty of other (better) converters out there which you may use. One strong note to point out is that, Sonic 1 uses 54 (Hex) chunks, multiplying this by 4 comes to 150 (Hex), which is far too much for the layout system as it must be FF or below, I found that I needed to delete chunks in LZ and SYZ simply because even after removing the duplicates, there were simply too many, you may need to take shortcuts in that department.

I'd like to thank NeKit and Irixion for helping me test and fish out the bugs (Though I'm sure you'll probably find something missed out, in which case I would be grateful in knowing what it is), Please do not note any of the common bugs such as the SEGA PCM, spike behaviour, etc, those bugs are not related to the 128x128 system and will not be fixed, that'll be down to you, if nothing else, have fun.

 

It works fine on my side using Version 1.03, and the "sep" files themselves seem ok, it could be the SonED 2 you're using is an older version, or possibly Direct X version? I don't actually know much about SonED in that department so that's all I can suggest I'm afraid.

To which I'll be looking forward to =)

 

To be fair, the engine itself only needed to be change correctly in a few spots, after working with the entire engine for about 2 years, it proved no problem at all, not much needed to be changed as the engine is structured to work for any size, why heck you could have 64x64 chunks in next to no time at all. The data however, is the real issue if anything, the fact that you are converting 54 (Hex) 256x256 chunks into FF (Hex) 128x128 chunks, means that for every 256x256 chunk, you'll get 4 128x128 chunks, so 54 x 4 = 150, 150 is far beyond the limit, of course there will no doubt be douplicate 128x128 chunks which can be erased removing 1 from the number of chunks, but this varies depending on the level involved, some will have enough douplicate chunks to reduce the number below 100, others won't, so revising and rationalising will be needed.

Fun facts: Sonic 1 has more chunk space in total, as it can use up to 150 (Hex) 128x128 chunks worth of 256x256 chunks, where Sonic 2 is stopped by the limit of FF, Sonic 1 can also hold more blocks, up to 7FF, while Sonic 2 is stuck with 3FF to make way for a second solid data ("Top, Left/Right, All" solid bits).