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Topics - tomaitheous

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ROM Hacking Discussion / Help with hacking Dracula X (Rondo)
« on: February 09, 2015, 10:07:23 pm »
I've had this info/knowledge for a bit: I found what appears to be a hidden super large monster in Dracula X for the PC-Engine CD.
Here's a few pics:

And some pics for what it might look like assembled:

I've messed around with the game and found the 'map' screen layout. This mini boss-ish character, is located right after the stage exit room: 01,02,03,04,05,06,05 ... with the first 05 entry being the sub-stage exit, and 06 being this boss character. Unfortunately changing this order does not effect any 'objects', AI, or any other attributes normally associated with that screen number.

 I can't seem to figure out the level engine/format. And to make matters worse, the game takes segments of ram in between code - so there is no specific section dedicated for 'ram' that I can spy on.. per se.

 Anyway, just trying to get some ideas. I spent quite a bit of time corrupting the ram areas that I know about, and found some related variables (but I haven't fully figured them all out; there are a lot of 'jump' table mechanisms for relative stage behavior). This being Konami, I figured that maybe they shared some design stuffs - that maybe someone could clue me in on? Or just different ideas to approach this. I've already spent a good amount of time tracing through asm, but my time is pretty minimal for this sort of thing at the moment.

February 11, 2015, 01:37:12 pm - (Auto Merged - Double Posts are not allowed before 7 days.)
No one, huh? Hmm.

Personal Projects / Game-2014 (homebrew game for PC-Engine/TG16)
« on: August 23, 2014, 04:35:22 pm »
Hey guys, I'm making an action-RPG game for the PCE/TG16. Old school style (over head/top-down).

 While I'm looking for some artists and people to help with the final project, I want to show off the game engine too. I have some lame-ish place holder stuffs/graphics.

 Anyone interested in making some place holder graphics for this 'demoing' of the game engine? Rip/modify whatever you want.
 I'll post requests of what kind of stuff I'm looking for here (and update the main thread). You'll get cred (end game credits for the finished one) for development if I end up using your stuffs in demoing/showing the game engine. These graphic assets are not final in game graphics. So you can rip and modify anything else for any other game.

 Here's an example of what I have so far for player and enemy sprites:

 Some specs: the game uses classic nes zelda style scrolling (screen to screen). The screen tiles are 16x16, and the screen size is 16x11. The player and regular enemies are 16x16 sized sprites. Larger enemies can be made.

 What I'm looking for so far:
 - items (money, crystals, etc)
 - different enemies
 - player sprites (different ones are fine). I was toying with the idea of having an second player option too.
 - enemy projectiles (whether they fly across the screen or not; could just be spears or sword swipes)
 - player projectiles (same as above)
 - enemy AI ideas/designs
 - player weapon/item ideas/designs. Falcom games are the influence of this homebrew, but there will be an attack button
 - dungeon/cave/town/house/outside tiles as well as maps designs.

 Immediate things that I need:
 - status bar design
 - item screen

 Are you border or looking for practice, or just wanna help out? Try your hand at any of the above. Any other ideas are welcome as well.

 Here's a screen shot of in game action:

^- the tiles aren't actually representative of what I want. The scale is wrong (i.e. those mountains, etc). I'm looking for something more proportional (Look at Zelda Alttp, or Legend of xanadu I, or Legend of Xanadu 2);

 Here's some specs to abide by:
 The master palette is 9bit. That means 8 shades for R/G/B elements. For editing (photoshop and such), I use RGB steps of 36. You can use the posterize function and set the levels to 8 to get the same effect/etc.
 Colors per sprite (16x16) are 15 colors. The PCE has 16 subpalettes just for sprites (separate from the BG).
 Colors per tile (8x8 hardware, but 16x16 for this game) is 15 colors (I'm reserving base color #0). There are 16 subpalettes for BG tiles.
 There is no tile flipping on this hardware. Only sprite cells can be flipped. That means you have to manually draw any flipped tiles.
 Sprites don't have to be limited to 16x16, but unless the enemy is tall or large - I'd like to keep most enemies at 16x16. I like that old school look.
 For now, only 8 enemies can be defined per screen (each screen has its own set).

Gaming Discussion / Homebrew related stuffs
« on: August 22, 2014, 04:44:01 pm »
I was wondering.. what about a sub-forum homebrew?

Also, I have a PCE/TG16 homebrew that I'm working on and looking for people (artists, musicians, writers, etc). Is there a specific place in the forums that I should post such a thread? Or is here pretty much the safe bet?

ROM Hacking Discussion / Asm hacking
« on: February 05, 2014, 04:43:40 pm »
Curious, how do you guys handle your ASM hacking projects?

 Do you use a hex editor to do all your asm hacking, or do you use an assembler? If you use an assembler, do you assembly directly into the rom or do copy the assembled code into the rom?

ROM Hacking Discussion / Need a sound effect for my title screen
« on: January 21, 2014, 12:30:40 am »
For when the title bar scrolls/snaps in over the background. Like a 'schwuuaaiiinnggg' type of noise. Something with a nice higher pitch metallic ring at the end. Maybe a few others for selection sounds (moving the cursor). They can be wave files or such, since they'll be ADPCM in for the game. Got any ideas/suggestions?

ROM Hacking Discussion / Need a menu and title/boot screen for Megaman
« on: January 14, 2014, 04:30:31 pm »
For this:

 I need to make a menu for when the game first boots. It allows setting the channel's (for PSG sound FX) stereo separation and as well as global PSG volume level. And difficulty mode setting.

 Anyone interested? The title/boot screen is shown before the game begins and doesn't replace the original title screen.

 I can put something generic there, but I figured why not add something custom/nice for a change. Looking to do this fairly soon.

 I'll give a few details: Title/boot screen image is 256x224. Tiles are 8x8. Each tile is 15 colors.  The color format is RGB, 9bit. To do it in something like Photoshop, use RGB steps of 36 (0,36,72,etc). For example R of RGB has 8 steps: 0, 36,72,108, 144, 180, 216, 252. Same for G and B. There are 16 subpalettes. Each subpalette holds 15 colors. A tile can be assigned to any of those 16 subpalettes; but only 1 subpalette per tile (doesn't matter where that tile is, in the pic). For photoshop, I usually just have a transparent overlay that's in a 8x8 grid - so that I can keep track of which tile uses which subpalette. Sound complicated? It's not. I can give a PSD example file of how it works.

 So, that's that. If you're interested, post some mock-ups here.

Edit: I was actually gonna use this:

But the I need a 'megaman' title, not a rockman one. And I need that 'megaman' title bar on a separate layer, so I can scroll it in. And since there's no detail underneath it, I can't (I'm not a good enough pixel artist to replace the BG detail).

Personal Projects / Street Figher 2 CE for PC-Engine
« on: December 29, 2013, 09:26:49 pm »
Current researching/hacking the game. I'll post info here, as I get it (making everything public).

 Also, if you're bored/curious/interested - help out. The 6280 is pretty much 65x code, so if you've done 6502 or 65816 stuffs before, then this should be second nature. Mednafen is the debugger of choice - currently. Post any info here. I'll do the same. :)

 Some info to start:

 Backgrounds are compressed. It's a simple mask+constant compression, for 8 byte chunks. Sprites are uncompressed. Palettes are bitpacked compressed;first two bytes contain the upper bit (Green) for the 9bit entry - for a block of 16 values. 16 bytes follow.

 As I get further along, I'll start putting info from here into docs and submit them to RHDN docs section.


ROM Hacking Discussion / Necromancer text compression scheme
« on: September 05, 2013, 09:59:00 pm »
I've done quite a bit of work with compression schemes in the past, but this one is pretty unfamiliar to me. It appears to be some sort of binary tree compression scheme.

 There's two varaibles; a down counter (always re/load with a value of $07, check looks for $ff value) and an byte bit mask.

 There's also a table/block. Each entry is either 2 or 3 bytes long (though there might be an entry that is 4 bytes long, IIRC). The ending byte is always $FF. So something like $97,$ff,$07,$ff,$85,$ff. #$ff is the terminator of each entry (which means skip to the next). The mask corresponding bit determines whether to skip 1 byte or two bytes. If two bytes, then the value from the 'block' or tree is added to the tree/block pointer, helping incrementing it. When a non termination value is read, it's passed to the string build routine, and then the tree pointer is reset back to the beginning of the block.

 There's also another block and pointer. When the down counter expires, this pointer is incremented and the mask is reloaded. Neither the base nor the index of the tree access system is reset at this point.

 There's another layer of mechanism in place as well. At the very start of the call, there's a variable that stops the string routine from accumulating. When this variable expires (decremented; 00 = expired), then it will copy valid string data to the string build routine. Else, it just accumulates the second pointer position.

 Soo... does this description sound familiar? Sound like a binary tree compression scheme? I'm on the verge of figuring it out; just need to trace back to the top layer function calls and hopefully begin test (and text) extract trials. Any advice or comments?


Personal Projects / Megaman 1 and 2 for PC-Engine upgrade/hack
« on: March 05, 2012, 04:34:49 pm »
I'm creating a project thread just for this game. Instead of the other thread that's about all NES conversions.

 Anyway, this thread is about upgrading Megaman 1 for the PCE with new sprites and tile abilities, adpcm sound FX (and psg as well), and CDDA or new PCEPSG sound track. Basically a hack for the hack ;)

 Please note, I'm looking for people that have experience with hacking Megaman on the NES. Low level hacking experience (changing code and such). I've seen some impressive hack work done out there for MM1 and I'd like to add some features to MM1 as well. Two completely new bosses would be nice (maybe like the Powered Up ones, I dunno). If you're interested, then lets talk. Or if you know someone with the skills, send them over here or to my blog (here would probably be better). You/they/him/her don't need to have PCE knowledge or experience. I'll handle that side of things. For them, it would be no different than hacking the original NES rom.

I don't need pixel artists just yet, I'll use place holder graphics to test out the upgraded functions meantime. I'll put out a want ad for that once I'm ready for that. I'm also gonna modify an existing sound engine for the PCE and use it for PCEPSG. So I'll be looking for some chiptune talent to make PCEPSG music remixes. Yeah, CDDA (red book) will be an option - but I happen to like the PCE sound chip and would to do something with it for this game.

 The game's primary platform is SuperCD. I do plan to make a hucard version (though it'll lack ADPCM and red book upgrades) for the mere fact that I'm going to be making some of my own hucards by hand/DIY project. I've love to have a hucard of the upgraded game for myself.

 The actual WIP stuff so far:

 - New title intro sequence (animation and such)
 - Easy mode for wusses ;)
 - save feature
 - 16 color sprites and tile
 - 16x16,32x16,32x32 sprite cell sizes
 - extended palette num to 8 for sprites
 - ADPCM sound fx
 - red book audio

It might be hard to notice at first, but the debugger pic there is showing off the 16x16,32x16, 32x32 sprite hacking that I've already started doing (old pic yeah, I'm too lazy to post something more recent).
I hacked the meta sprite table to just reference a single 32x32 sprite frame in memory. It means the sprite work is no longer limited to 8x8 cells of the original meta table.

 Edit: blog @

Personal Projects / PC-Engine Cribsheets
« on: February 04, 2011, 09:33:43 pm »
Figured only two kinds of people are probably gonna read these; homebrew/demo coders and hackers.

I uploaded them to the site document area, but here are the direct downloads:

 So far page 1 and 2 are done. If there are any changes, it'll be to be fix anything I might have missed.

 Page 3 and 4 are most likely going to be audio and video hardware.
 Page 5... I dunno. Probably CD/bios relative stuff (functions, special areas in ram for variables, etc) and maybe additional timing related stuff. These are primarily meant to be printed out. So you need a good printer and HQ paper. I tend to put these type of cheatsheets/cribsheets in clear plaster sleeves, etc. But you can still use them on your PC. I'd include a PDF with real text for searching, but the PDF builds I've made are very large for some reason (50megs) - so I haven't made them available. If people really want them, I'll upload them.

So, please post any comments/suggestions/feedback here.

Personal Projects / Megaman and other NES hacks for PCE
« on: August 04, 2008, 12:07:59 am »
 Update 1/21/14
 Working on lots of nes2pce stuff at the moment. Jackal as added to the list. Megaman 1 CD is about to be released, with redbook audio and a few other options (easy mode, stereo sound FX, 6 button gamepad support, etc).

 Update 7/25/11

 I've made some small updates to Megaman PPU and APU emulation. Screen now turns 'off' (though 1 frame delay) and the screen is better centered (can see the floor in Iceman's level).

 I've decided I should tackle some game challenges that actually motivate me. I like Contra, Robowarrior, etc but I'm just not really motivated enough to work on them. Like I have with Megaman. So, I've decided to pick to other games to work on that I think will keep up my motivation. Megaman 2 and Metroid. Work has already started on Megaman 2. I have to write new emulation code to support dynamic H and V mirroring changes/updates, but that's not too much of a problem as I've worked out the details. Megaman 2 only uses it for the stage select and map areas, nothing in game per se. So anyway, yeah.. Megaman 2. Should be fun.

Old news:

 Update 3/22/11
 - Links can be found at

 Update: 10/19/09
 - Added Duck Tales 2.

 Update: 10/14/09
  - Added Contra project to the list and links.

 Update: 10/10/09

 My site is gone, so the old links don't work. You can find current links here. I don't want to provide direct downloaded links here as the project files themselves more than likely violate the linking rules of this forum. Aside from that I haven't worked much on these, but did a few small audio bug fixes.

 Current NES to PCE projects:
 Megaman 1
 Castlevania 1
 Super Mario Bros 1
 Dragon Warrrior 1 (not uploaded yet)
 Duck Tales 2 (This isn't 100% tested to the end. Some sound/graphic port writes might be missing. Unconverted graphic port writes can freeze/glitch the game. I could use testers to play through this game.)

 I have some downtime coming up, so I'll probably try out some other simplish NES conversions.

 Note: This release should work with other emu's besides mednafen. Works on the real hardware.


 This a project to hack the original NES rom to run on the PCE. This method simulates/translates the PPU, APU, IO, and MAPPER on the backend of the system while the game code runs natively on the PCE's CPU. Writes and reads to I/O ports are replaced with JSRs. Once the game is up and running smoothly, additional modifications can be added like; upgraded audio(CD audio if CD project), 16color tiles/sprites, 512 color palette, bigger sprites, bigger sprite per scanline limit, up to 32megabit rom(if hucard - 600megabytes for CD), etc.

 This an open source project - so do what you want with it  ;)

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