Search found 33 matches

by OrangyTang
Thu Jan 25, 2024 9:26 pm
Forum: Exodus
Topic: Trying to compile Exodus
Replies: 8
Views: 14680

Re: Trying to compile Exodus

Turns out I still get email notifications, neat. I did get things compiling in the end, and wrote an enhanced asm window that ingested a .lst file so I could see comments/labels/etc. alongside the actual disassembly. I can dig out the source code if you want it, although I probably violated a bunch ...
by OrangyTang
Sun Dec 12, 2021 11:51 pm
Forum: Megadrive/Genesis
Topic: EXG instruction encoding
Replies: 4
Views: 7753

EXG instruction encoding

In an asm file (generated by Exodus' active disassembly) there's an EXG instruction at a particular address, like this: EXG D2, D0 Viewing the same location in several emulators (Exodus, Regen) shows the same instruction[1]. The raw value is 0xC540. Howevever, when I assemble my version into a binar...
by OrangyTang
Tue Dec 22, 2020 1:10 am
Forum: Exodus
Topic: Trying to compile Exodus
Replies: 8
Views: 14680

Re: Trying to compile Exodus

Sorry to resurrect an old thead, but I'm hitting the same snag - the latest source seems to have broken links for zlib and Catch. Are they available somewhere? I found an archived version of zlib 1.2.8, but am unsure what the nested directory should be called. Unzipping it directly gives Third/zlib/...
by OrangyTang
Fri Jun 19, 2020 12:56 pm
Forum: Megadrive/Genesis
Topic: Gunstar Heros disassembly?
Replies: 37
Views: 35064

Re: Gunstar Heros disassembly?

Anyway, besides that, I love seeing disassembles coming together and look forward to following along. I saw your other posts on here, looks like your understanding is coming along nicely. Thanks for the encoragement! Unfortunately progress has pretty much stalled due to lack of time (a common side ...
by OrangyTang
Mon Jan 06, 2020 11:28 am
Forum: Megadrive/Genesis
Topic: General Gunstar Heroes rambling
Replies: 5
Views: 9536

Re: General Gunstar Heroes rambling

I haven't identified those graphics yet, but so far *all* graphics other than the SEGA logo are compressed in ROM. I suspect the main characters will be loaded/unloaded as the game progresses, since there's an oddball scrolling-shooter level in the middle that uses completely different player sprites.
by OrangyTang
Wed Jan 01, 2020 3:49 pm
Forum: Megadrive/Genesis
Topic: General Gunstar Heroes rambling
Replies: 5
Views: 9536

Re: General Gunstar Heroes rambling

By standard colors, do you mean static colors? They don’t change at all so can be used by any foe, for example. Yes they're static and don't change for the whole game - at least during regular gameplay. Title screen, cutscenes and oddball gameplay (the scrolling shooter section) do their own thing....
by OrangyTang
Tue Dec 31, 2019 9:42 pm
Forum: Megadrive/Genesis
Topic: General Gunstar Heroes rambling
Replies: 5
Views: 9536

General Gunstar Heroes rambling

A while back I started disassembing Gunstar Heroes, got busy and shelved it. Over xmas I had some time to chip away at it, so I thought I'd put out a post with some of the things I discovered. In no particular order: The 'SEGA' animation at the start generates multiple scaled copes of the logo on th...
by OrangyTang
Thu Oct 11, 2018 2:15 pm
Forum: Megadrive/Genesis
Topic: Gunstar Heroes Decompression - Format & C# code
Replies: 5
Views: 8557

Re: Gunstar Heroes Decompression - Format & C# code

I finally got around to tidying up the code so the annotated asm routine from the rom and the c# version have been added to the original post. It's worked on all of the compressed data I've managed to find so far, but without the palletes it's still rather garbled and not clear what things are. So p...
by OrangyTang
Tue Oct 09, 2018 8:49 pm
Forum: Megadrive/Genesis
Topic: Gunstar Heroes Decompression - Format & C# code
Replies: 5
Views: 8557

Re: Gunstar Heroes Decompression - Format & C# code

It's tied in with the vblank code, I had a thread about it a while ago http://gendev.spritesmind.net/forum/viewtopic.php?f=2&t=2864 The loading system seems to have 7 'command' types known, one of which seems to decompress patterns to ram and then DMA to vram. The others I haven't figured out yet bu...
by OrangyTang
Tue Oct 09, 2018 6:33 pm
Forum: Megadrive/Genesis
Topic: simple 68k loop
Replies: 21
Views: 20387

Re: simple 68k loop

That looks like the interupt table at the start of a ROM. You can't get that any smaller, that's just what the MD rom format is, every rom has to have it.
by OrangyTang
Tue Oct 09, 2018 8:36 am
Forum: Megadrive/Genesis
Topic: Gunstar Heroes Decompression - Format & C# code
Replies: 5
Views: 8557

Re: Gunstar Heroes Decompression - Format & C# code

No, no exceptions. As you say, it stops when it has 32 decoded bytes. But since it's bit-based, the 'read cursor' may be pointing to (for example) the 3rd bit in the 7th byte. And it only needs three 16-bit values to store it's state in order to resume later.
by OrangyTang
Mon Oct 08, 2018 11:13 pm
Forum: Megadrive/Genesis
Topic: Gunstar Heroes Decompression - Format & C# code
Replies: 5
Views: 8557

Gunstar Heroes Decompression - Format & C# code

I've been poking at Gunstar Heroes off-and-on for a few months now, mostly just working away at the edges, but I finally managed to figure out the compressed data format. :D Here's the GH font, decompressed from raw rom bytes with some custom C# code: https://i.imgur.com/j6FbB1c.png Compressed data ...
by OrangyTang
Wed Sep 26, 2018 10:47 am
Forum: Exodus
Topic: Feature request - breakpoint highlighting
Replies: 0
Views: 80636

Feature request - breakpoint highlighting

Hello! I'm just getting used to the debugger and find that I'm adding a *lot* of breakpoints. Which is fine, but it quickly gets confusing figuring out which is which. Could there be some way of linking the breakpoints in the breakpoints window with the Disassembly view? Possible ideas: 1. 'Breakkpo...
by OrangyTang
Tue Sep 18, 2018 3:16 pm
Forum: Megadrive/Genesis
Topic: Neat programming trick for optional operations
Replies: 3
Views: 6624

Neat programming trick for optional operations

Since work is now less crunchy, I actually managed to find some time to work on my Gunstar Heroes disassem, and stumbled across a neat trick (apologies if this is already known but I thought it was cool): MOVE.w $FFFF8002.w, D0 ; var indicating which processing to perform ; 0 will never overflow (so...
by OrangyTang
Fri Apr 27, 2018 1:00 pm
Forum: Megadrive/Genesis
Topic: Struct maros/syntax and naming conventions
Replies: 6
Views: 8754

Re: Struct maros/syntax and naming conventions

So I dug out the old manual for snasm68k, and I think the 'rs' and 'rsset' macros are what I need (see page 27) : https://segaretro.org/images/0/04/SNASM68K_68000_Cross_Assembler_System_Manual.pdf However I can't actually figure ou the usage syntax atm. This works to define a struct, but actually us...