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Sonic CD in SMS

Discussion in 'Engineering & Reverse Engineering' started by chacanger, May 7, 2017.

  1. chacanger


    About a couple of years ago I realised that a member known as Kroc Camen was working on a Sonic 1 SMS ROM editing tool. This got me thinking about some ideas, looking at the hacking guide on this site, I was able to construct a crude level editor which allowed me to create Scrap Brain Zone Act 3 from the MD/Gen version and apply it to the SMS version (Seen in this video)

    However I then thought what if Ancient (the company who developed Sonic 1 SMS/GG version) made a version of Sonic CD for the SMS/GG (although the title wouldn't make much sense unless SEGA created some sort of Master CD/GGCD).

    Technically there's a huge amount of unused space within the game, and with the way the games art is compressed, it may be possible to create this albeit missing a couple levels. The palette limitations wouldn't really hinder what art could be created either. As a result I was able to create tile sets for the following...

    Pa = Past, Pr = Present, BF = Bad Future, GF = Good Future

    • Palmtree Panic Pa,Pr,BF,GF
    • Collision Chaos Pa,Pr,BF,GF
    • Tidal Tempest Pa,Pr,BF,GF
    • Quartz Quadrant Pa,Pr,BF,GF
    • Metallic Madness Pa,Pr,BF,GF
    • Title Screen
    • Zone Title Card
    • Capsule Art
    • Sonic Super Peel Out Art
    • Metal Sonic Sprites
    • Amy Sprites

    Here are some examples of how the art would look in game...

    Title Screen:

    Palmtree Panic:

    Collision Chaos:

    Tidal Tempest:

    Quartz Quadrant:

    Metallic Madness:

    In terms of the other levels, I had done a bit of work on Wacky Workbench, my ide would be to use the lightning conductors from Sky Base and re-texture them. Seeing as the springs are tiles in S1 opposed to objects, The springy floor would just be a re-texture of the springs.

    In terms of music, I tried editing existing music in game but it sounded awfull. ideally I could create some sort of MIDI to S1 SMS format tool to do this.

    It looks as though the editor that Kroc was working on hasn't been touched in quite a while, which is a shame, I myself had a go at making an application for it, but it wasn't very good as I didn't know enough about the ROM's details. So hopefully if someone manages to continue his work I could potentially finish this project.
  2. LoneDevil


    Eternal Underdog Member
    Gorgeous work there. I'm really hoping if there's ever gonna be a playable build exactly like in the screenshots above.

    One thing I forgot to point out is how much less unique objects can the SMS/GG have compared to the original (Sonic CD) for all the zones?
  3. This is awesome!! I'd love to see a finished build :) nice work
  4. DigitalDuck


    Arriving four years late. Member
    Lincs, UK
    TurBoa, S1RL
    Echoing above sentiments. This is awesome.
  5. chacanger


    Thanks LoneDevil, in terms of what I believe might not be possible...
    • 3D UFO special stages, I suspect it would be possible to create them using some sort of "Out Run 3-D" or "Space Harrier" code. though the amount of memory required to pull it off would probably be big enough to be a game in itself. Therefore my current idea is that the Time Stones are hidden within the levels themselves like with Sonic 1 SMS.
    • Intro and Ending Cutscenes, it would have to be some sort of sprite animation and would use up space that could be used put to better use.
    • Loop de Loops Sonic 1 SMS doesn't have any loop de loops due to the way collision and tile types work. Sonic 2 SMS/GG does but they run like automated sequences where you have no control. Sonic Chaos/Triple Trouble have better loops that work like they do in the MD games.
    Not a lot else I can think of at the moment. A lot of things could easily be miplemented such as...
    • Badniks , most could use the existing Sonic 1 Badnik code.
    • Time Travel , I reckon I'll use monitors opposed to sign posts, the checkpoints in the SMS/GG titles used arrow monitors so I'd like ot keep it consistent.
    • Bumpers The bumpers in Collision Chaos would use the Special Stage bumper/spring code.
    • Abilities Both the Super Peelout and Spin Dash should be possible to add without too much extra code.

    Really the main limitation here is how much memory gets used up. One of the ways of getting round this issue is to make the 4 time periods use a single tile sheet and swap the palettes when using Future or Past monitors.

    Another solution I had was to use a template level where I swap out certain tiles depending on the time period, which would save loads of space.

    Thanks High Fidelity, hopefully I'll submit it to SAGE one year. :thumbsup:/>
  6. Ravenfreak


    I dunno what I should put here. Tech Member
    O'Fallon Mo
    Hacking Sonic Drift, Writer at Sonic Cage Dome
    Ah it's nice to see someone hacking Sonic 1 SMS! This is the first 8-bit Sonic game I started hacking and made a pretty shitty disassembly, back when I was first teaching myself more about the SMS and Z80 ASM. Hopefully your tool can be fixed and released sometime in the future! I could never get Kroc's tool to work on my computer, and since I'm mainly focusing on Sonic 2/Chaos now, I didn't really do much with Sonic 1 SMS aside from moving some levels around and editing some palettes. I'm very intrigued by your project and I can't wait to see more! :) Also Sonic Chaos/Triple Trouble loops work like they do in Sonic 2 though you can actually go back through the loops unlike in Sonic 2. (Though in the Auto Demo you're actually able to go back through loops but it causes some issues and they probably couldn't fix them in time for the game's release so they just made it to where you can't move back through loops...)
  7. doc eggfan

    doc eggfan

    Are you pondering what I'm pondering? Wiki Sysop
    GreatMegaLD, GreatSC3k, Great SG1k
    Sonic FD?

    This looks mighty fine, but you might struggle to compromise and squeeze everything you want into RAM/VRAM. See my attempt to recreate Emerald Hill zone in Sonic 2 LD.
  8. Mastered Realm

    Mastered Realm

    A green crystal Member
    Is there any reason for the mostly blank BGs in the Sonic 8 bit games? Sonic 2's Underground zone has a nice mountain line, though.
  9. doc eggfan

    doc eggfan

    Are you pondering what I'm pondering? Wiki Sysop
    GreatMegaLD, GreatSC3k, Great SG1k
    There's essentially only one layer for both the foreground and background art. The mountain range in Underground zone is uninterrupted by foreground tiles, whereas if you tried to do that across the middle of the level, you'd need hundreds more variations of art tiles to account for that mountain range being covered by all the different combinations of sloping ground and walls etc.
  10. Ayu Tsukimiya

    Ayu Tsukimiya

    UGUU~ Member
    It's a shame there aren't that many 8-bit Sonic projects. Those mock up screenshots are insane.
  11. Fred


    Taking a break Oldbie
    Sonic 3 Unlocked
    Some of these seem a bit too hopeful, Quartz Quadrant in particular looks to use more art for the background than the foreground, but good god, man. Freakin' brilliant.
  12. ashthedragon


    Dragon Team Researcher
    Sonic Paradise & Sonic Ages
    This is gorgeus! 8 bits games deserve so much more attention, these mockups are beautiful!!! Hope it can be made!
  13. Titan


    Holy shit these are amazing, great work! Really hoping this becomes an actual hack but even the images are superb, I love 'what-if' things like this :)
  14. Black Squirrel

    Black Squirrel

    shaving is boring Wiki Sysop
    Northumberland, UK
    hey wiki you're so fine
    Yeah I had the same gut feeling that some of the more complicated backgrounds might not make the cut on real hardware, but it's definitely an interesting project. I'd love to see someone give it a go.

    I see you've realised Stardust Speedway is a non-starter - I guess trying to implement proper physics in an 8-bit Sonic title is a project in itself.
  15. nineko


    I am the Holy Cat Tech Member
    I considered doing such a thing (albeit with XM files instead of MIDI files of course), though I ended up never doing it because I was afraid that either Kroc or, more probably, ValleyBell would eventually supersede it (especially considering that he was the one who figured out the music format to begin with), thus rendering my efforts next to useless. This, combined to how niche 8-bit hackers are (much to my disappointment, because I like the 8-bit games), ultimately led me to dismiss the idea.

    Good luck for your project, though. I really like what you're doing here, which is something coming from me since I hate Sonic CD.
  16. Dee Liteyears

    Dee Liteyears

    deep in the past
    Spriting and hardly getting shit done
    Love those mockups. I just hope this project makes it further than Sonic2 LD. Good look with it! :)

    Also have a look at Triple Trouble's backdrops

    See how they cheated with the horizon being on various different heights? Neccessary due to the single tile plane, but it works because those areas are so far apart, you don't notice it.
  17. Qjimbo


    Your friendly neighbourhood lemming. Oldbie
    Great work, would love to see these screenshots "come to life" - also gives me more appreciation for the Master System's graphical style.
  18. Spanner


    The Tool Member
    United Kingdom
    Sonic Hacking Contest
    This certainly would be a great addition to this year's Sonic Hacking Contest if you manage to get something playable this year.
  19. Jassbec


    Lost Prototype Member
    Sonic Overture, Zeondrive
    So I got intrigued by this and made practically a music mockup for Palmtree Panic just for the hell of it. (I'd suggest lowering the volume a bit, render error)

    It's all SN76489 emulation so it's not running on the actual system, but I tried to stick to every limitation as closely as I could.
    I did not account for the channels needed for the sound effects though :v:
  20. Blastfrog


    See ya starside. Member
    This is fucking amazing, excellent work!

    However long this takes, I look forward to seeing what more you come up with.