A new discovery in Ristar hacking...

Kickass.

 

In Sonic 1, the first two bytes of the level format are the width and height, both minus one. (A 00 00 would mean that the level is one 256 mapping wide and tall. 02 01 would be 3 wide and 2 tall.)

I just checked the Ristar ROM and... it checks out. Two header bytes of Flora 1 are 17 and 03. Flora 1 is (17 + 1) * (03 + 1) = 60 Add the two byte header and get 62. Then the size of Flora 1 is 18894C (Flora 2 start) - 1888EA (Flora 1 start) = 62

Edit: Fixed first paragraph slightly.

 

Kickass. Now all someone needs to do is find the offsets for the object layouts.. =P Hell, I may be forced to dust off the ol' Hex editor and mess around with this.

 

hah awesome! does this mean we will have level hacks soon? ^_^ :D

 

OMG YES! Thanks a ton. This is some awesome info.
It's awesome when you do something that you don't think is possible for you to do, like when I realized pointers in Chaotix are normal + $700000. I thought you had to like, really understand the hardware to know that kind of stuff.

It might be possible to mod ESE to think Ristar is Sonic 1 and edit the levels with that. Who knows?

 

You can load a Ristar Savestate in ESE as a Sonic 1 savestate, and the level design will show up... however, the 16x16 data and the 128x128 data are off.

 

This is some awesome info. I don't really hack anything in Ristar except music (which is limited to porting), but this will help a lot of people, I'm sure.

 

Level layout in a save state is just linear memory. Sonic 1's real level layout format is packed to save space. Ristar is the same. No format is shared unless the same tools were used between Ristar and Sonic. I dubt it.
Ristar is newer than Sonic, and built by another people. They think differently. All they have is the idea of how Sonic work in Genesis hardware.

 

I listed some of the objects for the first level here, and sorry for some terrible descriptions:

Code (Text):

1. 00 - Nothing
2. 01 - Vine/Plant Thing
3. 02 - Small Grassy Platform
4. 03 - Left side of downward sloping platform
5. 04 - Straight Platform wtih two spike plants
6. 05 - Right Side of sloping up platform with ladder on side, then gap, then wooden thing that you grab to go on the other side
7. 06 - Two wooden thing that you grab to go to other side, left one short, right tall
8. 07 - Small low grassy platform
9. 08 - Left side of grassy platform in mid-air
10. 09 - Right side of grassy platform in mid-air, wooden thing sticking out on right (horizontal), gap, then very small platform with stick on it (vertical)
11. 0A - Left side of wall with ladder on side, and the top is shaped like  _/--\_
12. 0B - Right side of above, with two ladder rungs on ceiling at the end
13. 0C - Very right of above wall, but can be used with other things maybe. Two ladder rung on absolute left, 8 ladder rungs on ceiling
14. 0D - Wall platform, starts from absolute left. Two rungs on ceiling at start, then walking space, then wooden stick on it (vertical)
15. 0E - Three ladder rungs on absolute left, then gap, then wooden stick in mid-air (vertical)
16. 0F - Left side of long platform
17. 10 - Ground like this __/----  aka ground at begginning of normal level
18. 11 - Right side of above ground, looks like --\_|  had wall at end with four ladder rungs, and little platform at the top
19. 12 - Small platform a little lower than the one above, wall on right with 2 and a quater ladder rungs
20. 13 - Solid Wall
21. 14 - Ladder rungs on absolute left, and then flat, but high, ground
22. 15 - Ground like this _____/-\|  with wooden stick thing on right (vertical)
23. 16 - Middle of flat platform with wooden stick (vertical)
24. 17 - Continition of above platform with spike plant at the very right
25. 18 - Left facing horizontal stick in mid-air
26. 19 - Ground shaped like ______/-\
27. 1A - End of ground, right side, two ladder rungs on side, gap after
28. 1B - Left start of ground

 

Well, I've managed to get somewhat close to the real level... But apparently there are some differences in how the other data is stored, which makes sense.

 

By the way, the objects I listed aren't all of them, but that's all I had time to do for now.

 

Good work
!

 

Ristar don't really seem to get the attention it deserves. Galoob, the makers of Game Genie, never even made any codes for it. I was one of the few who bothered making any kind of codes for it.