[Dr. D'nar]

I have discovered that I am far too good at Sonic 2 for mine own health. Therefore, I return, briefly, to bring you a these codes. With the help of Regen's debugger and the very nice Sonic 2 disassembles, I managed to hack these codes together relatively easily. (Although, as a Z80 programmer, I find the 68K syntax to be backwards.) Each code is provided in both hex and Game Genie format. These are for NTSC.


Instant Death Mode
This code makes it so you die no matter how many rings you have. Shields still protect you.
03F894:4ef9
03f896:0003
03f898:f926
9H6A-G6YY
AS6A-GAE0
E56A-HX62


I found these in my notes. Not sure if they're original codes.

Disable Check Points:
01F298:4E75
R13A-C6Y2

Disable Checkpoints for Player 1
01F2AC:4E75
R13A-C6ZN

Disable Checkpoints for Player 2
01F332:4E75
R13T-C6VW


Because I know some people would complain that the above Instant Death Mode isn't a real DEZ mode because you can still get rings, I present this code. The rings still load, and the perfect bonus still counts down, but your ring count never goes up. Shields still protect you. This code just nops out the instruction that increments the ring count.

Death Egg Zone Mode (p1):
11FE0:0000
11FE2:0000
AAST-CAHA
AAST-CAHC

DEZ Mode (p2):
12032:0000
12034:0000
AATA-CABW
AATA-CABY


If you don't want shields to protect you, just don't get them.


Incidentally, since I am a Z80 programmer I may be able to provide help with sound programming. I've thought about making a Sonic clone for the TI-83+ series (itself based on the Z80), though I don't know enough about game design to do it.

[Billy]

These are pretty cool. It's nice to have some challenge in S2 again.

[Techokami]

If you're looking for something geared for your processor of choice, check out the Sonic 2 SMS disassembly in the SVN.

[Dr. D'nar]

Hmm, that might be an option. The TI-83 series has crappy display hardware, but I might actually be able to run this with four level gray scale on an SE/84 and still have CPU time leftover to actually run the game. The SE/84s run at 15MHz. The gray scale takes 50% of the CPU time, and I'd need lots of CPU time to process each frame for display. The plain TI-83+ runs at 6MHz, so I might be able to run that with monochrome graphics. I'd also be able to win the award for the largest application ever seriously published. Sadly, I don't have enough time to take on a project this big right now.

If Sega hasn't taken down this site yet, I don't suppose they'd care if I published a port.

[DimensionWarped]

Largest TI 83+ application? Maybe. But my TI 86 had all kinds of cheeky RPG games and even a low grade Sim City clone. I even managed to find a couple games that could individually take up all the memory on the device.

Granted, the 86 had less usable memory than the 83+ does... but damnit, it had build in assembly without needing to rely on shells!

This post has been edited by DimensionWarped: 07 October 2009 - 12:50 AM

[MainMemory]

The TI-83+ can run ASM programs without a shell too.