The Touhou PC-98 Restoration Project
πΌ π½ π Posted: 2026-03-16 22:58 UTC π Summary of: P0330 TH03 RE (Enemies / fireballs / explosions, part 1: Preparations + enemy state) P0331 TH03 decompilation (Enemies / fireballs / explosions, part 2: Fireball state / enemy functions) P0332 TH03 decompilation (Enemies / fireballs / explosions, part 3: Enemy functions) + Tooling (TH03 ENEDAT.DAT decompiler) P0333 TH03 decompilation (Enemies /β¦
πΌ π½ π Posted: 2025-12-31 22:43 UTC π Summary of: P0327 TH03 RE (Character-specific attack function pointers / Bullet dependencies / Bullet structure) P0328 TH03 decompilation (Bullets, part 1) P0329 TH03 decompilation (Bullets, part 2) / TwitterβFediverse migration, part 1 π° Funded by: [Anonymous], Ember2528 π·οΈ Tags: th03 rec98 website gameplay bullet micro-optimization mima-th03 kanaβ¦
πΌ π½ π Posted: 2025-10-19 21:52 UTC π Summary of: P0324 Seihou / Shuusou Gyoku (SDL 3 Windows 98 backport + Screenshot compression round-up) P0325 Seihou / Shuusou Gyoku (GCC β₯15 support / Resilient API configuration) + TH02-TH05 debloating round-up P0326 Seihou / Shuusou Gyoku (SDL 3 in frontend, part 1 + SDL 3 file I/O + Screenshot bugfixes) π° Funded by: Root, Ember2528 π·οΈ Tags:β¦
πΌ π½ π Posted: 2025-09-29 23:55 UTC π Summary of: P0319 Debloating / portability (TH02/TH03/TH04/TH05 cutscenes / TH04/TH05 High Score viewer / TH04/TH05 player selection / TH04/TH05 setup menu) P0320 Debloating / portability (TH02/TH03/TH04/TH05 Music Room / TH02/TH03/TH04/TH05 title screen and main menu / TH02 shot type selection) P0321 TH02-TH05 debloating (Scorefile cleanup / Merging OP.EXEβ¦
πΌ π½ π Posted: 2025-09-16 22:21 UTC π Summary of: P0317 TH02 RE (Main menu overhaul) / TH03 decompilation (High score menu, part 2/2) / TH02/TH03 debloating (Initial screen tearing fixes) P0318 TH04/TH05 decompilation (TH04 title screen animation / TH05 All Cast sequence / GENSOU.SCR, part 3/3) π° Funded by: Blue Bolt, [Anonymous], Yanga, Ember2528 π·οΈ Tags: th01 th02 th03 th04 th05 rec98 menuβ¦
πΌ π½ π Posted: 2025-09-10 23:56 UTC π Summary of: P0314 Research (Common blitting benchmark framework / Blitting performance of wide sprites) P0315 Debloating (Loading .PI images into planar buffers) P0316 Research (Crossfading benchmark) / Portability (Point, surface, and VBLANK abstractions) π° Funded by: [Anonymous], Congrio, Ember2528 π·οΈ Tags: rec98 pc98 blitting performance master.libβ¦
πΌ π½ π Posted: 2025-09-06 03:01 UTC π Summary of: P0313 Debloating (Build system preparations / TH01 cleanup) π° Funded by: Splashman , Ember2528 π·οΈ Tags: th01 th02 th03 th04 th05 rec98 portability emulation dosbox-x input palette menu Talk about a nerd snipe! I just wanted to take the first meaningful step towards getting PC-98 Touhou portable. But then, that step massively escalated andβ¦
πΌ π½ π Posted: 2025-08-12 π·οΈ Tags: seihou sh01 policy-bugfix gameplay rng Another replay desync bug in Shuusou Gyoku's Extra Stage that I accidentally introduced in P0295 and that therefore falls under my free bugfix policy ?! Last time, we were lucky and there was a general solution that would allow automatic repairs for affected replays inside the game, but not this time. That's right, theβ¦
πΌ π½ π Posted: 2025-05-20 π·οΈ Tags: seihou sh01 policy-bugfix replay Unfortunately, I have to quickly interrupt the current PC-98 Touhou progress with breaking news of a replay desync bug in my Shuusou Gyoku build. Yup, it's free mod bugfix time again, this time featuring a bug with the most complex implications so farβ¦ The Extra Stage replay desync bug introduced in P0295 How it happenedβ¦
πΌ π½ π Posted: 2025-05-10 20:41 UTC π Summary of: P0311 TH03 decompilation (Main menu, part 1/2) P0312 TH03 decompilation (Main menu, part 2/2 + Static HUD parts) + TH02 PI (Stage 3 midboss/boss state) + TH03 PI (Technical 100% for MAINL.EXE) π° Funded by: 32th System , [Anonymous], iruleatgames, Blue Bolt π·οΈ Tags: th02 th03 rec98 menu gaiji unused rng Surprise! The last missing main menu inβ¦
πΌ π½ π Posted: 2025-04-25 23:37 UTC π Summary of: P0310 Seihou / Shuusou Gyoku (SDL Windows 98 backport, part 1 / D3DWindower support) π° Funded by: Root, Arandui π·οΈ Tags: seihou sh01 portability Backporting my Shuusou Gyoku build to Windows 98 was one of my favorite commissions in recent history. If you remember π last year's backport of the overhauled ReC98 build system to Windows 9x , itβ¦
πΌ π½ π Posted: 2025-04-09 03:03 UTC π Summary of: P0307 Seihou / Shuusou Gyoku (SDL 3 platform layer) P0308 Seihou / Shuusou Gyoku (Render API unbricking / ReC98 build label on the title screen / Revamped pixel format handling) P0309 Seihou / Shuusou Gyoku (WebP screenshot compression / Compression benchmark in the main menu) π° Funded by: Ember2528 π·οΈ Tags: seihou sh01 policy-bugfix unusedβ¦
πΌ π½ π Posted: 2025-02-24 23:48 UTC π Summary of: P0304 TH02 RE (Stage / (mid)boss variables) + Decompilation (Bullets, part 1/2) P0305 TH02 decompilation (Bullets, part 2/2 + Sparks, part 1/2) P0306 TH02 decompilation (Player, part 1/2: Update/render functions + Miss animation) + Random TH04/TH05 finalization π° Funded by: Yanga, iruleatgames, nrook, [Anonymous] π·οΈ Tags: th02 th03 th04 th05β¦
πΌ π½ π Posted: 2025-01-25 23:56 UTC π Summary of: M0003 Seihou / Shuusou Gyoku (Icon commission from Mr. Tremolo Measure) P0299 tupblocks (Clang and GCC support) P0300 Seihou / Shuusou Gyoku (Build portability + Game logic portability, part 4/4 + SDL threads) P0301 Seihou / Shuusou Gyoku (Pango/Cairo text rendering, part 1/2) P0302 Seihou / Shuusou Gyoku (Pango/Cairo text rendering, part 2/2 +β¦
πΌ π½ π Posted: 2024-12-04 14:29 UTC π Summary of: P0298 TH04/TH05 finalization (GENSOU.SCR, part 2/3) + Decompilation (High Score view screen) π° Funded by: Blue Bolt, [Anonymous], Splashman π·οΈ Tags: th04 th05 rec98 file-format score menu bgm kaja hidden-content master.lib palette TH05's OP.EXE ? It's not one of the π main blockers for multilingual translation support , but fine, let's pushβ¦
πΌ π½ π Posted: 2024-11-22 04:00 UTC π Summary of: P0296 Website / Blog (Post list page + Navigation and post header redesign) P0297 TH03 decompilation (Character selection screen) π° Funded by: [Anonymous], 32th System π·οΈ Tags: th03 website rec98 pc98 emulation animation menu performance palette Remember when ReC98 was about researching the PC-98 Touhou games? After over half a year, we'reβ¦
πΌ π½ π Posted: 2024-10-22 05:18 UTC π Summary of: P0286 tupblocks ( import std; support) P0287 Seihou / Shuusou Gyoku (Code cleanup + Game logic portability, part 2/? + Fixes for bugs and landmines) P0288 Seihou / Shuusou Gyoku (Getting pbg's code through static analysis) P0289 Seihou / Shuusou Gyoku (Game logic portability, part 3/? + Graphics refactoring, part 3/5: Preparations and colors)β¦
πΌ π½ π Posted: 2024-07-09 11:30 UTC π Summary of: P0002 Build system improvements, part 2 (Preparations / Codebase cleanup) P0003 Build system improvements, part 3 (Lua rewrite of the Tupfile / Tup bugfixes for MS-DOS Player) P0004 Build system improvements, part 4 (Merging the 16-bit build part into the Tupfile) P0281 Build system improvements, part 5 (MS-DOS Player bugfixes and performanceβ¦
πΌ π½ π Posted: 2024-04-24 13:14 UTC π Summary of: P0280 TH03 RE (Coordinate transformations / Player entity movement / Global shared hitbox / Hit circles) π° Funded by: Blue Bolt, JonathKane, [Anonymous] π·οΈ Tags: th03 rec98 meta performance micro-optimization emulation dosbox-x animation pc98 TH03 gameplay! π It's been over two years. People have been investing some decent money with theβ¦
πΌ π½ π Posted: 2024-04-11 22:45 UTC π Summary of: P0278 TH02 decompilation (Endings) P0279 TH02 decompilation (Staff Roll + Verdict screen + Stage bonus tables) π° Funded by: Yanga π·οΈ Tags: th02 rec98 cutscene file-format animation pc98 unused midboss waste score sigma That was quick: In a surprising turn of events, Romantique Tp themselves came in just one day after the last blog post wentβ¦
πΌ π½ π Posted: 2024-03-09 15:23 UTC π Summary of: P0266 mly (CLI preparation + MIDI event dumping + Basic loop detection algorithm) P0267 mly (Refined loop detection algorithm + SMF Type 0 conversion + Cut/unfold operations) P0268 mly (Recording-space loops + Rendering helpers) + Seihou / Shuusou Gyoku (BGM packs, part 1/?: Sound Canvas VA versions) P0269 Seihou / Shuusou Gyoku (BGM packs, partβ¦
πΌ π½ π Posted: 2024-02-03 08:03 UTC π Summary of: P0264 TH03/TH04/TH05 decompilation (Music Rooms, part 1/2) P0265 TH03/TH04/TH05 decompilation (Music Rooms, part 2/2 + MAINE.EXE main()) + TH02 PI/RE (Boss damage and position) π° Funded by: Blue Bolt, [Anonymous], iruleatgames π·οΈ Tags: th02 th03 th04 th05 rec98 policy-bugfix menu animation master.lib pc98 file-format cutscene boss midbossβ¦
πΌ π½ π Posted: 2023-11-30 23:56 UTC π Summary of: P0262 Decompilation (TH04/TH05 main/option menu) P0263 Decompilation (TH04/TH05 first-launch sound setup menu + TH05 title screen animation) π° Funded by: Blue Bolt, [Anonymous] π·οΈ Tags: th04 th05 rec98 website menu waste file-format animation And once again, the Shuusou Gyoku task was too complex to be satisfyingly solved within a singleβ¦
πΌ π½ π Posted: 2023-11-01 23:58 UTC π Summary of: P0258 Decompilation (TH04/TH05 stage dialogs, part 1/2) P0259 Decompilation (TH04/TH05 stage dialogs, part 2/2) + TH02 RE (Stage dialog preparations) P0260 Decompilation (TH02 stage dialogs, part 1/2) P0261 Decompilation (TH02 stage dialogs, part 2/2 + TH03 win messages + TH04/TH05 MIKO.CFG + TH04 game startup) π° Funded by: Blue Bolt,β¦
πΌ π½ π Posted: 2023-09-30 21:01 UTC π Summary of: P0252 Seihou / Shuusou Gyoku (Building SDL from source within Tup) P0253 Seihou / Shuusou Gyoku (Game logic portability, part 1/? + Cross-platform APIs, part 1/?: Window creation via SDL) P0254 Seihou / Shuusou Gyoku (Cross-platform APIs, part 2/?: Sound via miniaudio) P0255 Seihou / Shuusou Gyoku (Cross-platform APIs, part 3/?: Input via SDL)β¦
πΌ π½ π Posted: 2023-08-01 23:57 UTC π Summary of: P0246 Seihou / Shuusou Gyoku (Cleanup and deduplication) P0247 Seihou / Shuusou Gyoku (Graphics refactoring, part 1/5) P0248 Seihou / Shuusou Gyoku (η§ιCFG.DAT versioning) P0249 Seihou / Shuusou Gyoku (Graphics refactoring, part 2/5 + Coordinate systems, part 1/?) P0250 Seihou / Shuusou Gyoku (Text pre-rendering, part 1/2: Implementation +β¦
πΌ π½ π Posted: 2023-07-28 π·οΈ Tags: meta Yet another small interruption before we get to Shuusou Gyoku, but only because I've got a big announcement to make! Touhou Patch Center has just commissioned the basic feature set that would allow PC-98 Touhou to be translated into non-ASCII languages. π° And we're in fact doing it on PC-98, and don't wait for the games to be ported to other systemsβ¦
πΌ π½ π Posted: 2023-06-30 23:52 UTC π Summary of: P0245 TH04/TH05 finalization (Sprite clipping + gather circles + boss explosions) + TH01 Anniversary Edition (Lines, part 1/?) π° Funded by: Blue Bolt, Ember2528, [Anonymous] π·οΈ Tags: th02 th04 th05 rec98 midboss blitting animation master.lib pc98 uth05win debloating And then, the supposed boilerplate code revealed yet another confusing issueβ¦
πΌ π½ π Posted: 2023-06-13 11:07 UTC π Summary of: P0244 TH04 PI/RE (Stage 4 carpet lighting effect + 100% PI) π° Funded by: Blue Bolt, [Anonymous] π·οΈ Tags: th04 th05 rec98 position-independence stage animation gameplay jank yuuka-6 shot π After almost 3 years, TH04 finally caught up to TH05 and is now 100% position-independent as well! π For a refresher on what this means and does not mean,β¦
πΌ π½ π Posted: 2023-06-07 23:17 UTC π Summary of: P0242 TH02 RE (Score tracking + HUD rendering) P0243 TH02 RE (Items) π° Funded by: Yanga π·οΈ Tags: th02 rec98 gameplay item rng enemy score hud stones OK, let's decompile TH02's HUD code first, gain a solid understanding of how increasing the score works, and then look at the item system of this game. Should be no big deal, no surprisesβ¦
πΌ π½ π Posted: 2023-05-29 23:39 UTC π Summary of: P0240 TH04 PI/RE (Stage 5 star rendering + Stage 6 Yuuka checkerboard + Custom entity structures, part 1/2) P0241 TH04 PI/RE (Custom entity structures, part 2/2 + Thick laser structure + PI false positives + .STD loading) π° Funded by: JonathKane, Blue Bolt, [Anonymous] π·οΈ Tags: th03 th04 th05 rec98 meta seihou sh01 bullet boss kurumi reimu-4β¦
πΌ π½ π Posted: 2023-05-01 23:56 UTC π Summary of: P0238 Website (TypeScript migration + Stripe integration, part 1/2: Basic support) P0239 Website (Stripe integration, part 2/2: Subscription support) + TH01 Anniversary Edition (Minor bugfixes) π° Funded by: Ember2528 π·οΈ Tags: th01 website rec98 meta anniversary-edition debloating master.lib cutscene animation debug Stripe is now properlyβ¦
πΌ π½ π Posted: 2023-03-30 13:23 UTC π Summary of: P0235 TH02 RE (Stage tiles, part 1/2) P0236 TH02 RE (Stage tiles, part 2/2) P0237 TH02 RE (Spark structure + Point number popups + Bomb animation effects) π° Funded by: Ember2528, Yanga π·οΈ Tags: th02 th04 th05 rec98 stage blitting micro-optimization unused tcc So, TH02! Being the only game whose main binary hadn't seen any dedicated attentionβ¦
πΌ π½ π Posted: 2023-03-14 π·οΈ Tags: rec98 th01 policy-bugfix anniversary-edition gameplay bullet boss sariel Turns out I was not quite done with the TH01 Anniversary Edition yet. You might have noticed some white streaks at the beginning of Sariel's second form, which are in fact a bug that I accidentally added to the initial release. These can be traced back to a quirk I wasn't aware of, andβ¦
πΌ π½ π Posted: 2023-03-05 12:56 UTC π Summary of: P0229 TH01 debloating (Single-executable build, part 1/2) P0230 TH01 debloating (Single-executable build, part 2/2) P0231 Research (Spawning TSRs from C) P0232 Portability (PC-98 platform layer, part 1) P0233 Research (Performance of various PC-98 blitting approaches) P0234 TH01 Anniversary Edition (Removing interlaced pellet rendering + Mergingβ¦
πΌ π½ π Posted: 2023-01-17 17:52 UTC π Summary of: P0227 TH05 decompilation (Sara) / Research (Relativity of near references) P0228 TH05 finalization (Lasers) π° Funded by: nrook, [Anonymous] π·οΈ Tags: th01 th04 th05 rec98 gameplay boss sara tcc laser micro-optimization glitch Starting the year with a delivery that wasn't delayed until the last day of the month for once, nice! Still, very soonβ¦
πΌ π½ π Posted: 2022-12-31 23:57 UTC π Summary of: P0226 Seihou / Shuusou Gyoku (Running at full speed on modern systems / Basic locale independence) π° Funded by: Arandui , alp-bib π·οΈ Tags: seihou sh01 meta cutscene unused file-format > "OK, TH03/TH04/TH05 cutscenes done, let's quickly finish the Touhou Patch Center MediaWiki upgrade. Just some scripting and verification left, it will be doneβ¦
πΌ π½ π Posted: 2022-11-30 22:20 UTC π Summary of: P0223 TH03/TH04/TH05 decompilation (Cutscenes, part 1/3: State + Box and picture rendering) P0224 TH03/TH04/TH05 decompilation (Cutscenes, part 2/3: Script commpands) P0225 TH03/TH04/TH05 decompilation (Cutscenes, part 3/3: Interpreter loop + TH05 rendering boilerplate, part 1/?) π° Funded by: rosenrose, Blue Bolt, Splashman , -Tom- , Yanga,β¦
πΌ π½ π Posted: 2022-10-31 23:58 UTC π Summary of: P0218 Website (Video pipeline, part 1/2: Preparations / Source file gathering) P0219 Website (Video pipeline, part 2/2: Encoding / Tweaking settings / Caching) P0220 Website (Video player, part 1/3: Basic controls and frame-accurate seeking) P0221 Website (Video player, part 2/3: Tabs and markers) P0222 Website (Video player, part 3/3: Dynamicβ¦
πΌ π½ π Posted: 2022-09-04 15:13 UTC π Summary of: P0217 Seihou / Shuusou Gyoku (Clean-room packfile implementation / Building a drop-in replacement binary) π° Funded by: Arandui π·οΈ Tags: seihou sh01 build-process First of all: This blog is now available as a web feed, in three different formats! /blog/feed.xml /blog/feed.atom /blog/feed.json Thanks to handlerug for implementing and PR'ing theβ¦
πΌ π½ π Posted: 2022-08-15 23:57 UTC π Summary of: P0216 TH01 decompilation (100%) π° Funded by: JonathKane π·οΈ Tags: th01 rec98 meta On August 15, 1997, at Comiket 52, an unknown doujin developer going by the name of ZUN released his first game, ζ±ζΉιη°δΌ ο½ The Highly Responsive to Prayers , marking the start of the Touhou Project game series that keeps running to this day. Today, exactly 25 yearsβ¦
πΌ π½ π Posted: 2022-08-14 23:17 UTC π Summary of: P0214 TH01 decompilation (Orb and Game Over animations + Pause, continue, and debug menus) P0215 TH01 decompilation (REIIDEN.EXE main() function / 100%) π° Funded by: Ember2528, Yanga π·οΈ Tags: th01 rec98 animation blitting score card-flipping glitch rng debug Last blog post before the 100% completion of TH01! The final parts of REIIDEN.EXEβ¦
πΌ π½ π Posted: 2022-08-11 21:27 UTC π Summary of: P0212 TH01 decompilation (Stage bonus and TOTLE screens, part 1/2) P0213 TH01 decompilation (Stage bonus and TOTLE screens, part 2/2 + Data finalization, part 2/2 + FUUIN.EXE 100%) π° Funded by: LeyDud, Lmocinemod , GhostRiderCog, Ember2528 π·οΈ Tags: th01 rec98 score pc98 performance unused cutscene debug Wow, it's been 3 days and I'm alreadyβ¦
πΌ π½ π Posted: 2022-08-08 18:23 UTC π Summary of: P0207 TH01 decompilation (YuugenMagan, part 1/5: Preparation) P0208 TH01 decompilation (YuugenMagan, part 2/5: Helper functions) P0209 TH01 decompilation (YuugenMagan, part 3/5: Main function) P0210 TH01 decompilation (YuugenMagan, part 4/5: Eye opening/closing + ιͺ colors) P0211 TH01 decompilation (YuugenMagan, part 5/5: Quirk research + Dataβ¦
πΌ π½ π Posted: 2022-07-17 19:20 UTC π Summary of: P0205 TH01 decompilation (Mima, part 1/2: Patterns 1-4) P0206 TH01 decompilation (Mima, part 2/2: Patterns 5-8 + main function) + Research (TH01's unexpected palette changes) π° Funded by: [Anonymous], Yanga π·οΈ Tags: th01 rec98 gameplay boss mima-th01 danmaku-pattern rng performance palette glitch jank konngara meta Oh look, it's another ratherβ¦
πΌ π½ π Posted: 2022-07-10 11:48 UTC π Summary of: P0203 TH01 decompilation (Card-flipping stages, part 3/4: Bumpers and turrets) P0204 TH01 decompilation (Card-flipping stages, part 4/4: Portals + Bomb animation) π° Funded by: GhostRiderCog, [Anonymous], Yanga π·οΈ Tags: th01 rec98 meta gameplay card-flipping player shot mod rng bomb waste Let's start right with the milestones: More than 50% ofβ¦
πΌ π½ π Posted: 2022-06-25 16:39 UTC π Summary of: P0201 TH01 decompilation (SinGyoku, part 1/2: Preparation + sphere movement + patterns 1-2) P0202 TH01 decompilation (SinGyoku, part 2/2: Patterns 3-6 + main function + Missiles, part 2/2 + YuugenMagan setup) π° Funded by: Ember2528, Yanga, [Anonymous] π·οΈ Tags: th01 rec98 gameplay boss singyoku blitting glitch animation bullet The positive: Itβ¦
πΌ π½ π Posted: 2022-06-17 17:03 UTC π Summary of: P0198 TH01 decompilation (Kikuri, part 1/3: Preparation + soul, tear, and ripple animations) P0199 TH01 decompilation (Kikuri, part 2/3: Patterns) P0200 TH01 decompilation (Kikuri, part 3/3: Main function + Ending boss slideshow + Good/Bad endings) π° Funded by: Ember2528, Lmocinemod , Yanga π·οΈ Tags: th01 rec98 gameplay boss kikuri blittingβ¦
πΌ π½ π Posted: 2022-05-31 23:43 UTC π Summary of: P0193 TH01 decompilation (Elis, part 1/4: Preparations + patterns 1-3) P0194 TH01 decompilation (Elis, part 2/4: Patterns 4-6 + transformations) P0195 TH01 decompilation (Elis, part 3/4: Patterns 7-13) P0196 TH01 decompilation (Elis, part 4/4: Entrance animation + main function) P0197 TH01 research (HP bar heap corruption + boss defeat crashes)β¦
πΌ π½ π Posted: 2022-04-30 22:58 UTC π Summary of: P0190 TH05 decompilation (Shinki, part 1/2: Patterns 1-10) P0191 TH05 decompilation (Shinki, part 2/2: Pattern 11, main function) P0192 TH05 decompilation (Stage 1 midboss + Replay file format) + Separating translation units, part 11 π° Funded by: nrook, -Tom- , [Anonymous] π·οΈ Tags: th02 th03 th04 th05 rec98 gameplay boss shinki danmaku-patternβ¦