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ReC98 @ReC98Project

The Touhou PC-98 Restoration Project. Decompiled 100% of TH01 to provably legit C code, remaining games in progress. Which mods or ports do *you* want to see?

Joined February 2015
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ReC98@ReC98Project
5 Oct 2019
Replying to @ReC98Project
Website is done, and the crowdfunding is now live! rec98.nmlgc.net Please invest responsibly.
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140-175 ms for simulating the full 7 minutes of Shuusou Gyoku's Extra Stage on the command line. On an 8-year-old Core i5. Single-threaded. With MSVC's horrid codegen and several untapped optimization opportunities. And that's the heaviest case. Regular stages are much faster.
Output of the upcoming Shuusou Gyoku command-line replay simulation tool, showing the end result of two Extra Stage and one Lunatic Stage 4 replay, together with the surprisingly short amount of time it took to gather these results – 141.3 ms for a Wide Shot Extra Stage run, 173.3 ms for a Homing Missile Extra Stage run, and 44.8 ms for a Laser run of Stage 4 on Lunatic difficulty, translating to validation frame rates of 191894, 151244 and 242082 FPS, respectively.

ALT Output of the upcoming Shuusou Gyoku command-line replay simulation tool, showing the end result of two Extra Stage and one Lunatic Stage 4 replay, together with the surprisingly short amount of time it took to gather these results – 141.3 ms for a Wide Shot Extra Stage run, 173.3 ms for a Homing Missile Extra Stage run, and 44.8 ms for a Laser run of Stage 4 on Lunatic difficulty, translating to validation frame rates of 191894, 151244 and 242082 FPS, respectively.

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Of course, this also means instant detection of desyncs. (Though only via a Game Over occurring before the game processed all inputs, since that's all data we have in the old format. The new one will record more events that could pinpoint the cause of a desync more closely.)
Output of the upcoming Shuusou Gyoku command-line replay simulation tool, showing a desyncing replay that ends 77.1% into the recorded replay data with a Game Over, after just 24.6 ms of simulation time.

ALT Output of the upcoming Shuusou Gyoku command-line replay simulation tool, showing a desyncing replay that ends 77.1% into the recorded replay data with a Game Over, after just 24.6 ms of simulation time.
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Finally, Shuusou Gyoku's game logic, isolated in a reusable, freestanding DLL. No global state. No Win32 API dependencies besides GetProcessHeap(), HeapAlloc(), and HeapFree(). No instructions newer than i586. Still simulates blazingly fast. (Have fun guessing how fast exactly!)
Screenshot of the Windows 11 Properties dialog displaying the new Shuusou Gyoku game logic DLL, with a size of 73,216 bytes.

ALT Screenshot of the Windows 11 Properties dialog displaying the new Shuusou Gyoku game logic DLL, with a size of 73,216 bytes.

Screenshot of Dependency Walker running on Windows 98 displaying the new Shuusou Gyoku game logic DLL and showing off its minimal imports of GetProcessHeap(), HeapAlloc(), and HeapFree().

ALT Screenshot of Dependency Walker running on Windows 98 displaying the new Shuusou Gyoku game logic DLL and showing off its minimal imports of GetProcessHeap(), HeapAlloc(), and HeapFree().
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ReC98 retweeted
ReC98@ReC98Project
Jun 13
(Yes, I've heard the news and will go right back to work! Just let me finish this really cool thing for Shuusou Gyoku I've been working on for the past few months, and then I'm going to spend an extended amount of time with the main business. OK?)
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sizeof(C_SSG) is 403,280 bytes on 32-bit systems, and 405,664 bytes on 64-bit systems.
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(Yes, I've heard the news and will go right back to work! Just let me finish this really cool thing for Shuusou Gyoku I've been working on for the past few months, and then I'm going to spend an extended amount of time with the main business. OK?)
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Many thanks to this month's subscribers! The splitting process has escalated to not only cover Shuusou Gyoku's logic, but also my SDL-based engine, laying the groundwork for future modern-system builds. Only missing the CLI now, and of course the blog post. Mid-June, maybe?
Active ReC98 subscriptions for May 2026: • €125 from [Anonymous] towards anything (including tooling) • €50 from Ember2528 towards better replays for Shuusou Gyoku, followed by a long-term plan to first decompile TH03, adding replays, porting it to modern systems, and then implementing netplay (although we're also going for a more short-term option of having netplay on PC-98) • €35 from [Anonymous] towards TH03 RE • €10 from Root towards porting SDL to Windows 98 to get Shuusou Gyoku running there again

ALT Active ReC98 subscriptions for May 2026: • €125 from [Anonymous] towards anything (including tooling) • €50 from Ember2528 towards better replays for Shuusou Gyoku, followed by a long-term plan to first decompile TH03, adding replays, porting it to modern systems, and then implementing netplay (although we're also going for a more short-term option of having netplay on PC-98) • €35 from [Anonymous] towards TH03 RE • €10 from Root towards porting SDL to Windows 98 to get Shuusou Gyoku running there again
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Full list of seemingly decorative aspects in Shuusou Gyoku that are actually game logic and must always be simulated because they draw from and advance the single global RNG: • The hearts shown when losing a life • The sparks shown when grazing bullets or hitting an enemy
First Shuusou Gyoku comparison screenshot of the randomness in 1) the hearts shown when losing a life, and 2) the sparks shown when grazing bullets. Taken at the start of Stage 5.

ALT First Shuusou Gyoku comparison screenshot of the randomness in 1) the hearts shown when losing a life, and 2) the sparks shown when grazing bullets. Taken at the start of Stage 5.

Second Shuusou Gyoku comparison screenshot of the randomness in 1) the hearts shown when losing a life, and 2) the sparks shown when grazing bullets. Taken at the start of Stage 5.

ALT Second Shuusou Gyoku comparison screenshot of the randomness in 1) the hearts shown when losing a life, and 2) the sparks shown when grazing bullets. Taken at the start of Stage 5.

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• The falling stars in the last phase of the Gates fight, and in Stage 6 • Boss explosions • The background animations in Stage 6 (wavy clock, wireframe cubes, and …
First Shuusou Gyoku comparison screenshot of the randomness in Stage 6's wavy clock background and falling stars. Taken at the start of VIVIT-captured-'s first phase, on the specific frame before her first pattern.

ALT First Shuusou Gyoku comparison screenshot of the randomness in Stage 6's wavy clock background and falling stars. Taken at the start of VIVIT-captured-'s first phase, on the specific frame before her first pattern.

Second Shuusou Gyoku comparison screenshot of the randomness in Stage 6's wavy clock background and falling stars. Taken at the start of VIVIT-captured-'s first phase, on the specific frame before her first pattern.

ALT Second Shuusou Gyoku comparison screenshot of the randomness in Stage 6's wavy clock background and falling stars. Taken at the start of VIVIT-captured-'s first phase, on the specific frame before her first pattern.

First Shuusou Gyoku comparison screenshot of the randomness in boss explosions and Stage 6's wireframe cubes. Taken during the entrance animation of VIVIT-captured-'s second phase.

ALT First Shuusou Gyoku comparison screenshot of the randomness in boss explosions and Stage 6's wireframe cubes. Taken during the entrance animation of VIVIT-captured-'s second phase.

Second Shuusou Gyoku comparison screenshot of the randomness in boss explosions and Stage 6's wireframe cubes. Taken during the entrance animation of VIVIT-captured-'s second phase.

ALT Second Shuusou Gyoku comparison screenshot of the randomness in boss explosions and Stage 6's wireframe cubes. Taken during the entrance animation of VIVIT-captured-'s second phase.

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• …fake script code) • The text popups shown for boss defeat and Evade bonuses or when collecting a bomb or extra life, where each letter flies off at a different angle • The sprintf() implementation that decides the number of letters (and thus, RNG steps) in these popups (!)
First Shuusou Gyoku comparison screenshot of the randomness in Stage 6's fake script code, shown all throughout VIVIT-captured-'s third phase. Taken during that phase's entrance animation.

ALT First Shuusou Gyoku comparison screenshot of the randomness in Stage 6's fake script code, shown all throughout VIVIT-captured-'s third phase. Taken during that phase's entrance animation.

Second Shuusou Gyoku comparison screenshot of the randomness in Stage 6's fake script code, shown all throughout VIVIT-captured-'s third phase. Taken during that phase's entrance animation.

ALT Second Shuusou Gyoku comparison screenshot of the randomness in Stage 6's fake script code, shown all throughout VIVIT-captured-'s third phase. Taken during that phase's entrance animation.

First Shuusou Gyoku comparison screenshot of the randomness in the per-letter scatter effect at the end of each text popup. Taken during the Stage 1 midboss, where it also contrasts the static parts of its pattern against the random ones.

ALT First Shuusou Gyoku comparison screenshot of the randomness in the per-letter scatter effect at the end of each text popup. Taken during the Stage 1 midboss, where it also contrasts the static parts of its pattern against the random ones.

Second Shuusou Gyoku comparison screenshot of the randomness in the per-letter scatter effect at the end of each text popup. Taken during the Stage 1 midboss, where it also contrasts the static parts of its pattern against the random ones.

ALT Second Shuusou Gyoku comparison screenshot of the randomness in the per-letter scatter effect at the end of each text popup. Taken during the Stage 1 midboss, where it also contrasts the static parts of its pattern against the random ones.
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Point items in Shuusou Gyoku will award negative points if you collect them below the bottom edge of the playfield during the respawn animation. And nobody noticed because 1) the game's 5×7-digit font doesn't have a - sign, and 2) the total score can't decrease, only increase.
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… that's *not* the score that the game would record in the High Score list. Shuusou Gyoku only ever adds potential negative deltas to the score on a Game Over – not when switching stages, and not when clearing the game. And we obviously don't want to change such scoring details.
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Thus, negative item values will continue to just "absorb" points from subsequently collected positive-value items like they did in the original game, and not immediately decrease the score. Some zoomed-in images variants for comparison: (fixed → original → ≥P0295 && ≤P0326)
Zoomed-in screenshot of incorrectly rendered item popups with negative values as they will appear in the ReC98 P0339 build of Shuusou Gyoku.

ALT Zoomed-in screenshot of incorrectly rendered item popups with negative values as they will appear in the ReC98 P0339 build of Shuusou Gyoku.

Zoomed-in screenshot of incorrectly rendered item popups with negative values as they appear in the original 1.005 release of Shuusou Gyoku. The four bottom popups represent the actual internal values of (from bottom to top) -6400, -4000, 5600, and -1920, yet all negative values are rendered without the leading minus sign and therefore wrongly appear to be positive.

ALT Zoomed-in screenshot of incorrectly rendered item popups with negative values as they appear in the original 1.005 release of Shuusou Gyoku. The four bottom popups represent the actual internal values of (from bottom to top) -6400, -4000, 5600, and -1920, yet all negative values are rendered without the leading minus sign and therefore wrongly appear to be positive.

Zoomed-in screenshot of incorrectly rendered item popups with negative values as they appear in any ReC98 build ≥P0295 and ≤P0326. The four bottom popups represent the actual internal values of (from bottom to top) -6400, -4000, 5600, and -1920, but the negative values are instead rendered as the obviously 32-bit-integer-overflowed values 4294960896, 4294963296, and 4294965376 due to a signedness confusion in an sprintf() format string.

ALT Zoomed-in screenshot of incorrectly rendered item popups with negative values as they appear in any ReC98 build ≥P0295 and ≤P0326. The four bottom popups represent the actual internal values of (from bottom to top) -6400, -4000, 5600, and -1920, but the negative values are instead rendered as the obviously 32-bit-integer-overflowed values 4294960896, 4294963296, and 4294965376 due to a signedness confusion in an sprintf() format string.
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Hilarious Shuusou Gyoku pbg quirk dropping later today
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What's this? A MinGW fork with GCC 15 that targets Windows 98? Small package, no bullshit? Tested and working fine for trivial programs? github.com/redpanda-cpp/ming… Removing the KernelEx and SSE instruction requirements from Shuusou Gyoku's backport has just become a lot cheaper.

GitHub - redpanda-cpp/mingw-lite: MinGW-w64 GCC distribution. Fast and flexible build scripts;...

MinGW-w64 GCC distribution. Fast and flexible build scripts; minimal dependencies; works on NT 4.0 and 98. Inspired by w64devkit. - redpanda-cpp/mingw-lite

github.com
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Although not entirely free, and it would come with a one-time setup cost and the drawbacks of abandoning the current strategy. So it's up to the backers to decide. More info: github.com/nmlgc/ssg/issues/…

Support compilation with MinGW · Issue #80 · nmlgc/ssg

Might give us a Windows 98 backport that is more stable in the long run than continuously chasing and polyfilling the current Windows SDK bundled with the current Visual Studio. Doesn't actuall...

github.com
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Many thanks to this month's subscribers! Very slow month, but I still managed to move enough code to push the headless Shuusou Gyoku subproject to over 100 commits. Very close to solving the hardest issues while juggling Windows 9x and FFI use cases. 4 pushes for sure, though.
Active ReC98 subscriptions for April 2026: • €125 from [Anonymous] towards anything (including tooling) • €50 from Ember2528 towards better replays for Shuusou Gyoku, followed by a long-term plan to first decompile TH03, adding replays, porting it to modern systems, and then implementing netplay (although we're also going for a more short-term option of having netplay on PC-98) • €35 from [Anonymous] towards TH03 RE • €10 from Root towards porting SDL2 to Windows 98 to get Shuusou Gyoku running there again

ALT Active ReC98 subscriptions for April 2026: • €125 from [Anonymous] towards anything (including tooling) • €50 from Ember2528 towards better replays for Shuusou Gyoku, followed by a long-term plan to first decompile TH03, adding replays, porting it to modern systems, and then implementing netplay (although we're also going for a more short-term option of having netplay on PC-98) • €35 from [Anonymous] towards TH03 RE • €10 from Root towards porting SDL2 to Windows 98 to get Shuusou Gyoku running there again
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