Title screen mappings format help -- Sonic 2 SMS

I want to enter mappings for title screen, but there's no info about the format whatsoever. I tried asking this in QA thread, but my question got no attention and was flooded by other questions. Wonderful.

Anyway, I wanna ask 2 questions:

• What's the format?
• Is this some sort of special format or this is a general plane mapping format for SMS?

 

The thread's title says title card while the post says title screen. Which one do you want to change?

The Community Hacking Guide for the 8 bit version of Sonic 1 says that RLE compression is used for the title screen mappings among other things. You can read about it here. It's a safe bet that Sonic 2 uses it for the title screen and the title cards.

To be fair, there aren't many SMS hackers around here.

 

Well, what a mistake! xD

I'll fix

 

If you're wanting to edit the title screen, you'll have to use Aspect Edit and edit the tiles rather than the mappings. (Aspect Edit cannot edit mappings, and I haven't really bothered to look into how the mappings even really work that much.) Because of this, you'll have to edit each individual tile, like you did with Green Hills Zone. Sorry I didn't see your question in the other topic, I would have responded to it if I did. :V

 

Sorry, but it's all but a safe bet. 8-bit Sonic 1 was developed Ancient and Sonic 2/Chaos/Triple Trouble were developed by Aspect.
IIRC Sonic 1 SMS/GG uses a few unique compression algorithms. (It has a custom sound driver for sure.)