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FINALLY seeing my recent hard work on my accelerated linear algebra and math library, SH4ZAM, for the Sega Dreamcast pay off for our community infrastructure and libraries, holy shit. What you are seeing is two direct hardware captures of our Mario Kart 64 port running on actual DC hardware,... playing the most taxing stage in 2-player coop mode. The top frame was the release build, which uses the standard GLdc OpenGL 1.2 driver implementation for all of its rendering. The bottom frame is a new build I just made using an experimental branch of GLdc which I have accelerated using SH4ZAM... Most of what I've done so far has been swapping to my optimized memcpy() and store-queue copying routines and backing the GL stack with my vectorized SH4 ASM implementations of the GL transform routines... I've introduced a few regressions into some of the GLdc test/example programs, but for the most part, everything is actually working, and I'm finally seeing some real-world gainz from accelerating our community infrastructure instead of just single applications!show more

Falco Girgis

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29,743 views • 4 months ago •via X (Twitter)

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Soooooo... What is going to be the next Nintendo 64 classic jnmartin ports to the Sega Dreamcast? He's decided that before he starts something new, he would like to go revisit our Super Mario 64 port and apply all of the infrastructure, gainz, and wisdom from the other ports... Once again, I have joined the party, armed with my SH4ZAM accelerated vector math library for the Dreamcast's SH4 CPU. ...and once again, I'm over here totally screwing up all of the math on the hunt for gainz. Here's a direct hardware capture of my latest matrix math mistake for the scrapbook!

Soooooo... What is going to be the next Nintendo 64 classic jnmartin ports to the Sega Dreamcast? He's decided that before he starts something new, he would like to go revisit our Super Mario 64 port and apply all of the infrastructure, gainz, and wisdom from the other ports... Once again, I have joined the party, armed with my SH4ZAM accelerated vector math library for the Dreamcast's SH4 CPU. ...and once again, I'm over here totally screwing up all of the math on the hunt for gainz. Here's a direct hardware capture of my latest matrix math mistake for the scrapbook!

Falco Girgis

50,251 views • 6 months ago

Got something totally different, but exceptionally badass today to share! Here is a bunch of direct hardware captures of the (F)ixed (F)unction and (F)ast (F)ourier (T)ransform (T)esting audio visualization demos, running on my Sega Dreamcast! This incredible piece of science, engineering, art, and music started off as a crazy idea to port a bunch of GPU-based, Shadertoy audiovisual demos to the Sega Dreamcast, to play with combined digital signal processing and rendering on legacy fixed-function hardware. As you can see from the video, the FFFFTT repo includes a wide array of different demos, each providing different kinds of visualizations, each featuring different types of signal transformations and analyses, with many of them also being interactive, all done in real-time! Not only that, but you ALSO can freaking pause the playback and analyze the signals in real-time... crazy! The final resulting FFFFTT demos are an epic full-stack conglomeration of Ray's raylib, providing the backing infrastructure and graphics framework, which sits atop our GLdc driver for rendering, using David Reid's miniaudio library for sound playback, with its FFT and vector algebra accelerated for the SH4 CPU using my SH4ZAM math library... all ontop of KallistiOS, running on the Sega Dreamcast! Congratulations to meisei4 for the fantastic accomplishments, and a heart-felt thanks from me for bringing everything together to make this happen! You just laid the framework for some epic audio-based gameplay mechanics and other crazy science experiments in the future for whole community!

Got something totally different, but exceptionally badass today to share! Here is a bunch of direct hardware captures of the (F)ixed (F)unction and (F)ast (F)ourier (T)ransform (T)esting audio visualization demos, running on my Sega Dreamcast! This incredible piece of science, engineering, art, and music started off as a crazy idea to port a bunch of GPU-based, Shadertoy audiovisual demos to the Sega Dreamcast, to play with combined digital signal processing and rendering on legacy fixed-function hardware. As you can see from the video, the FFFFTT repo includes a wide array of different demos, each providing different kinds of visualizations, each featuring different types of signal transformations and analyses, with many of them also being interactive, all done in real-time! Not only that, but you ALSO can freaking pause the playback and analyze the signals in real-time... crazy! The final resulting FFFFTT demos are an epic full-stack conglomeration of Ray's raylib, providing the backing infrastructure and graphics framework, which sits atop our GLdc driver for rendering, using David Reid's miniaudio library for sound playback, with its FFT and vector algebra accelerated for the SH4 CPU using my SH4ZAM math library... all ontop of KallistiOS, running on the Sega Dreamcast! Congratulations to meisei4 for the fantastic accomplishments, and a heart-felt thanks from me for bringing everything together to make this happen! You just laid the framework for some epic audio-based gameplay mechanics and other crazy science experiments in the future for whole community!

Falco Girgis

12,566 views • 18 days ago

Some interesting Sega Dreamcast science I've been doing on the side recently... Here's a direct hardware capture of a tech demo of Bruce's aptly-named "Dreamcast Mesh Shit," featuring assets from... Uhhh... I don't even know where he jacked these from... 😂 ANYWAY, the main thing I've been working on is optimizing the skinning for the animations using my SH4ZAM fast math and linear algebra library, which can easily become one of the primary bottlenecks when running the late 6th generation games on the Dreamcast. My work has been mostly to allow the vast majority of the skinning math to occur in the SH4's XMTRX back-bank of floating-point registers, rather than having to round-trip to and from memory for every operation... Just shaved off a few hundred microseconds per mesh this way, with a lot more room to go. Once I have this stuff SOLID, I plan to bring it back to our DC port of Grand Theft Auto: Vice City, where skinning was one of the major contributors to FPS dips.

Some interesting Sega Dreamcast science I've been doing on the side recently... Here's a direct hardware capture of a tech demo of Bruce's aptly-named "Dreamcast Mesh Shit," featuring assets from... Uhhh... I don't even know where he jacked these from... 😂 ANYWAY, the main thing I've been working on is optimizing the skinning for the animations using my SH4ZAM fast math and linear algebra library, which can easily become one of the primary bottlenecks when running the late 6th generation games on the Dreamcast. My work has been mostly to allow the vast majority of the skinning math to occur in the SH4's XMTRX back-bank of floating-point registers, rather than having to round-trip to and from memory for every operation... Just shaved off a few hundred microseconds per mesh this way, with a lot more room to go. Once I have this stuff SOLID, I plan to bring it back to our DC port of Grand Theft Auto: Vice City, where skinning was one of the major contributors to FPS dips.

Falco Girgis

49,078 views • 3 months ago

Today we have a direct hardware capture of an upcoming Sega Dreamcast homebrew title, tentatively known as "DemoTek," from developer, ac3t1ne, whose goal is to create a Crash Bandicoot-style platformer. The game uses our GLdc implementation of OpenGL 1.2 for rendering, libADX for music, and with my own SH4ZAM library for vector math, all of which are first-party ports provided within the KallistiOS indie DC SDK. The engine already features a renderer with some fairly aggressive batching and pre-submission culling, some clever LOD tricks and frame blending (notice the lava animates at twice the FPS when the player is close to it), as well as a particle system, which drives the smoke and bubbles. Something that I find quite interesting and exciting is that ac3t1ne has also managed to create a kind of update manager which can check for newer versions of the game (or any other Dreamcast binary), then download it via dial-up modem or broadband adapter, and install it onto an SD card! Be sure to check out ac3t1ne's YouTube channel for more updates:

Today we have a direct hardware capture of an upcoming Sega Dreamcast homebrew title, tentatively known as "DemoTek," from developer, ac3t1ne, whose goal is to create a Crash Bandicoot-style platformer. The game uses our GLdc implementation of OpenGL 1.2 for rendering, libADX for music, and with my own SH4ZAM library for vector math, all of which are first-party ports provided within the KallistiOS indie DC SDK. The engine already features a renderer with some fairly aggressive batching and pre-submission culling, some clever LOD tricks and frame blending (notice the lava animates at twice the FPS when the player is close to it), as well as a particle system, which drives the smoke and bubbles. Something that I find quite interesting and exciting is that ac3t1ne has also managed to create a kind of update manager which can check for newer versions of the game (or any other Dreamcast binary), then download it via dial-up modem or broadband adapter, and install it onto an SD card! Be sure to check out ac3t1ne's YouTube channel for more updates:

Falco Girgis

12,421 views • 2 months ago

The time has finally come! Here's an actual hardware capture of me cruising through Corneria in jnmartin's port of Star Fox 64 running on the Sega Dreamcast! As you can see, the port has been progressing PHENOMENALLY over the last couple months. Everything plays super smoothly and is as responsive as lightning! The visuals also look clean and crisp rendered at 480p with the DC's PowerVR GPU. We're estimating that the port is about 95% completed, with the majority of the last few weeks being spent implementing the lighting and other special effects for certain areas (which you will soon be seeing as well). Finally, he's been working daily on JIT compiling the N64 display list code into SH4 assembly in real-time in addition to using my SH4ZAM library for what he hopes will be a final round of additional performance gainz! TL;DR: We have another AAA-quality Nintendo 64-to-Sega Dreamcast jnmartin port on our hands here! Stay tuned for the upcoming release!

The time has finally come! Here's an actual hardware capture of me cruising through Corneria in jnmartin's port of Star Fox 64 running on the Sega Dreamcast! As you can see, the port has been progressing PHENOMENALLY over the last couple months. Everything plays super smoothly and is as responsive as lightning! The visuals also look clean and crisp rendered at 480p with the DC's PowerVR GPU. We're estimating that the port is about 95% completed, with the majority of the last few weeks being spent implementing the lighting and other special effects for certain areas (which you will soon be seeing as well). Finally, he's been working daily on JIT compiling the N64 display list code into SH4 assembly in real-time in addition to using my SH4ZAM library for what he hopes will be a final round of additional performance gainz! TL;DR: We have another AAA-quality Nintendo 64-to-Sega Dreamcast jnmartin port on our hands here! Stay tuned for the upcoming release!

Falco Girgis

35,196 views • 8 months ago

This is a direct hardware capture of our Grand Theft Auto 3 port running on the Sega Dreamcast... which I'm still constantly receiving questions about to this day... So what's the deal? Do we ever plan to revisit it, or have we called it a day and moved on? What about all of these gainz that I keep posting about, surely they could be applied to our GTA3 and VC ports? The truth is... No, I'm not done. I constantly think about the day when SH4ZAM is ready to be pulled back into the codebase for what will hopefully be another round of epic gainz. GTA3 and VC on DC were probably the most exhilarating, satisfying projects I've ever worked on as an engineer--academically, professionally, and personally. SH4ZAM literally started out as hand-optimized inline ASM routines I was whipping out of my ass to optimize the physics and TnL for these ports... but I decided to extract the routines and develop SH4ZAM in isolation for a couple reasons: 1) I saw a gaping hole in the DC homebrew community and KallistiOS ecosystem, which prevented indie developers from truly harnessing the power of the DC's SH4 CPU and its epic FPU, due to us having no good generic software solution to democratize the hardware... I felt like my work on GTA3 and VC could help fill that void. 2) The linear algebra math and low level SH4 ASM was starting to get complex enough that continuing to work within the main game codebase when implementing these optimizations became unrealistic. It became too easy to break the game in obscure ways that weren't immediately apparent without playing the game for hours, which was not a very ideal workflow... I needed an isolated environment where I could rigorously unit test and profile my routines. In addition to SH4ZAM, though, there's all kinds of other stuff I wanted for the game... We have yet to implement mouse + keyboard support for the PC control scheme, also enabling players enter cheat codes. We had some cool goodies planned for the VMU, and we didn't support any rumble or haptic feedback either, just to name a few. Finally, we have one more super secret weapon we've kept hidden for many months now... A certain 3D modeling wizard, who goes by Andrea Lotito, has been working on asset-side gainz, by reducing polygonal complexity of pedestrian models among others, while astonishingly still managing to get EVEN MORE DETAIL out of the models as well?!

Falco Girgis

34,216 views • 2 months ago

jnmartin and I just spent the last 12 hours straight locked into an epic tag-team, binge-coding session. We've decided to return to perfect our port of Mario Kart 64 to the Sega Dreamcast, bringing with us all of the skills, knowledge, and tools at our disposal that we gained from every port we've been involved with since we originally released MK64 DC to the public. 1) jnmartin has just completely redone the audio synthesis and mixing code. It was originally emulating the Nintendo 64's RSP in software, on our CPU, and wound up being a total resource hog, despite us going to hell and back again, substantially boosting its performance by vectorizing it with our SH4 SIMD instructions. 2) Now that the audio is actually offloaded to the AICA, we can leverage its DSP to put back in effects such as reverb and echo that we simply didn't have the CPU budget to implement before... so the overall audio quality of the port will be SIGNIFICANTLY improved. 3) jnmartin has been working on many small bugfixes, such as the near-Z clipping edge-cases that would cause corrupted triangles to draw over the players' screens sometimes in 3 and 4 player modes. 4) jnmartin just kicked GLdc--our OpenGL 1.1 driver, built atop of KallistiOS--to the curb and has instead implemented a bare-metal renderer that raw-dogs KOS's lowest-level PVR GPU driver directly, giving us more control and better performance within the renderer. 4) I just implemented support for playing with the Sega Dreamcast keyboard peripheral as a controller, partially as a flex, and partially because jnmartin kept complaining that he only had 3 controllers for testing... 🤣 4) I have taken my entire accelerated math and linear algebra library, SH4ZAM--which was born just after this port was originally released--back with me this time and am optimizing every freaking thing I can get my hands on with it. Every matrix multiplication, vector transform, memcpy-call, and scalar or trig routine is getting swapped out for the corresponding hand-optimized, meticulously benchmarked, and rigorously unit-tested equivalent within SH4ZAM, which now ships as part of kos-ports. As you can see from this series of direct hardware captures, overlaid with the terminal window which was capturing the FPS logging reports from my actual Sega Dreamcast, the performance is now SIGNIFICANTLY better than it was previously, and it already ran on-par or slightly better than the N64 original under most circumstances! Sooo many GAINZ to be had! 💪

jnmartin and I just spent the last 12 hours straight locked into an epic tag-team, binge-coding session. We've decided to return to perfect our port of Mario Kart 64 to the Sega Dreamcast, bringing with us all of the skills, knowledge, and tools at our disposal that we gained from every port we've been involved with since we originally released MK64 DC to the public. 1) jnmartin has just completely redone the audio synthesis and mixing code. It was originally emulating the Nintendo 64's RSP in software, on our CPU, and wound up being a total resource hog, despite us going to hell and back again, substantially boosting its performance by vectorizing it with our SH4 SIMD instructions. 2) Now that the audio is actually offloaded to the AICA, we can leverage its DSP to put back in effects such as reverb and echo that we simply didn't have the CPU budget to implement before... so the overall audio quality of the port will be SIGNIFICANTLY improved. 3) jnmartin has been working on many small bugfixes, such as the near-Z clipping edge-cases that would cause corrupted triangles to draw over the players' screens sometimes in 3 and 4 player modes. 4) jnmartin just kicked GLdc--our OpenGL 1.1 driver, built atop of KallistiOS--to the curb and has instead implemented a bare-metal renderer that raw-dogs KOS's lowest-level PVR GPU driver directly, giving us more control and better performance within the renderer. 4) I just implemented support for playing with the Sega Dreamcast keyboard peripheral as a controller, partially as a flex, and partially because jnmartin kept complaining that he only had 3 controllers for testing... 🤣 4) I have taken my entire accelerated math and linear algebra library, SH4ZAM--which was born just after this port was originally released--back with me this time and am optimizing every freaking thing I can get my hands on with it. Every matrix multiplication, vector transform, memcpy-call, and scalar or trig routine is getting swapped out for the corresponding hand-optimized, meticulously benchmarked, and rigorously unit-tested equivalent within SH4ZAM, which now ships as part of kos-ports. As you can see from this series of direct hardware captures, overlaid with the terminal window which was capturing the FPS logging reports from my actual Sega Dreamcast, the performance is now SIGNIFICANTLY better than it was previously, and it already ran on-par or slightly better than the N64 original under most circumstances! Sooo many GAINZ to be had! 💪

Falco Girgis

12,615 views • 12 days ago

FINALLY finishing up a MASSIVE PR from hell for the Sega Dreamcast port of Grand Theft Auto 3! This is an actual hardware capture now of the DC version under a high load, which would've previously been a slideshow, between the dynamic lighting from the sirens, the amount of rigid bodies in the physics simulation from the cars, and the high-speed chase placing high-demands on asset streaming... I went through all of the low-level common math infrastructure in both the engine and at the RenderWare driver layer and made numerous optimizations, before slowly working my way up to optimizing individual algorithms at the application layer using the new math routines. Firstly, the common low-level floating-point math routines for everything from trig and inverse square root operations to floor(), ceiling(), and clamp(), were replaced with what was meticulously found (in Compiler Explorer) to be the optimal patterns for GCC 14.2.0, targeting our SH architecture (sometimes favoring C builtins, sometimes inline SH4 ASM). Next, in the layer above, with inline SH4 assembly, the common matrix math and linear algebra routines were accelerated using the Dreamcast's vector instructions. Some cleverness went down here, such as cramming matrix metadata into unused insignificant bits of an element, combining loading two matrices with multiplying them, fast transposes, fast quaternion multiplication using 4 dot products, etc. Once the foundation was laid, some of the Renderware code such as the calculations for the lighting, updating bounding volumes, and deriving UV coordinates for specular environment maps on the cars was made faster automatically. The main gainz were actually made rewriting a decent amount of the collision intersection and contact resolution code, though, from using C++-style overloaded operators for multiplying single 4D vectors by a 4x4 matrix to doing batches of 4D vectors by the same matrix. This SUBSTANTIALLY reduced the number of times the backing 4x4 matrix bank had to be reloaded and allowed me to keep it resident within registers while it was being used by the intersection algorithms!

FINALLY finishing up a MASSIVE PR from hell for the Sega Dreamcast port of Grand Theft Auto 3! This is an actual hardware capture now of the DC version under a high load, which would've previously been a slideshow, between the dynamic lighting from the sirens, the amount of rigid bodies in the physics simulation from the cars, and the high-speed chase placing high-demands on asset streaming... I went through all of the low-level common math infrastructure in both the engine and at the RenderWare driver layer and made numerous optimizations, before slowly working my way up to optimizing individual algorithms at the application layer using the new math routines. Firstly, the common low-level floating-point math routines for everything from trig and inverse square root operations to floor(), ceiling(), and clamp(), were replaced with what was meticulously found (in Compiler Explorer) to be the optimal patterns for GCC 14.2.0, targeting our SH architecture (sometimes favoring C builtins, sometimes inline SH4 ASM). Next, in the layer above, with inline SH4 assembly, the common matrix math and linear algebra routines were accelerated using the Dreamcast's vector instructions. Some cleverness went down here, such as cramming matrix metadata into unused insignificant bits of an element, combining loading two matrices with multiplying them, fast transposes, fast quaternion multiplication using 4 dot products, etc. Once the foundation was laid, some of the Renderware code such as the calculations for the lighting, updating bounding volumes, and deriving UV coordinates for specular environment maps on the cars was made faster automatically. The main gainz were actually made rewriting a decent amount of the collision intersection and contact resolution code, though, from using C++-style overloaded operators for multiplying single 4D vectors by a 4x4 matrix to doing batches of 4D vectors by the same matrix. This SUBSTANTIALLY reduced the number of times the backing 4x4 matrix bank had to be reloaded and allowed me to keep it resident within registers while it was being used by the intersection algorithms!

Falco Girgis

114,524 views • 1 year ago

With all of the excitement from Mario Kart 64 coming to the Sega Dreamcast, I've been getting bombarded with questions about whether any more progress has been made on our Mario 64 port... so here's a direct hardware capture of the latest build running on DC! The answer: HELL YES! Last time most people saw or played this port, it was plagued with performance, audio, and graphical issues... but as you can see from this footage, almost all of them have been resolved, and she's playing like a dream on the DC now! Wtf happened? Well, first of all, in the 5 years since the port initially started, I, along with others, such as UnknownShadow, have made progress optimizing and improving upon our OpenGL 1.2 driver, "GLdc," which drastically improved the overall performance of the port by decreasing the amount of time the Dreamcast's SH4 CPU spent on T&L, processing polygons. Next, chad developer, Bruce (or Bruck or Brucilicious, depending on who you are), went through and applied a bunch of bugfix patches from the upstream repo to the game to fix the majority of the graphical glitches such as clipping issues and Mario's iconic biker mustache from the previous releases (despite me trying to convince him to keep that one, as it's become a Dreamcast trademark). Finally, the original developer behind both the Sega Dreamcast and Sony PSP ports, MrNeo, has returned from hiatus and has begun redoing the audio engine to fix the artifacting and stuttering! Stay tuned for further updates and the inevitable rerelease of this N64 classic on Sega's finest little white box that still refuses to die!

With all of the excitement from Mario Kart 64 coming to the Sega Dreamcast, I've been getting bombarded with questions about whether any more progress has been made on our Mario 64 port... so here's a direct hardware capture of the latest build running on DC! The answer: HELL YES! Last time most people saw or played this port, it was plagued with performance, audio, and graphical issues... but as you can see from this footage, almost all of them have been resolved, and she's playing like a dream on the DC now! Wtf happened? Well, first of all, in the 5 years since the port initially started, I, along with others, such as UnknownShadow, have made progress optimizing and improving upon our OpenGL 1.2 driver, "GLdc," which drastically improved the overall performance of the port by decreasing the amount of time the Dreamcast's SH4 CPU spent on T&L, processing polygons. Next, chad developer, Bruce (or Bruck or Brucilicious, depending on who you are), went through and applied a bunch of bugfix patches from the upstream repo to the game to fix the majority of the graphical glitches such as clipping issues and Mario's iconic biker mustache from the previous releases (despite me trying to convince him to keep that one, as it's become a Dreamcast trademark). Finally, the original developer behind both the Sega Dreamcast and Sony PSP ports, MrNeo, has returned from hiatus and has begun redoing the audio engine to fix the artifacting and stuttering! Stay tuned for further updates and the inevitable rerelease of this N64 classic on Sega's finest little white box that still refuses to die!

Falco Girgis

34,186 views • 1 year ago

Been up almost the entire night making big audio gainz on the SH4 CPU for the Sega Dreamcast port of Mario Kart 64! It took about 3 of us pitching ideas and optimizing together, but holy shit, the 200Mhz SH4 is keeping up 99% of the time doing all synthesis and mixing in SW! What you're seeing is the first hardware capture of Mario Kart 64 running on the Sega Dreamcast with working audio playback... and trust me, it was not easy to get here! First of all, all of the audio signal processing for synthesizing individual notes from sampling instruments then mixing the SFX channels and the BGM together into a single audio stream is being done completely in SW on the DC's 200Mhz SH4 CPU--while it was done in HW on the N64. It is also carrying the whole T&L load for rendering with extra overhead per draw call due to us using our OpenGL 1.1 driver for graphics (GLdc). You can currently see a teeny little bit of slowdown at the beginning of the race when all 8 karts are bunched together, emitting their own SFX, which all has to get mixed in SW, bogging down the CPU... but don't worry, plenty of gainz left! On the left is a very interesting routine which proved to be incredibly gainzy when accelerated... So lets jump into what we did to this "aResampleImpl()" routine! 1) Compiler Optimizations: Everything is compiled with -Os by default to save RAM, because jnmartin is preloading almost everything up-front; however, we've created a "hot file" listing within the Makefile which allows us to build specific perf-critical translation units at with the -O3 optimization flag. 2) Manually managing the data cache: notice how many prefetches and barriers are in this routine in order to phenangle GCC's codegen to be somewhat similar to the ordering we've done things in C. Additionally, I've gone through hell in Compiler Explorer to ensure that all of the buffers used here can be prefetched in a timely manner, so that they're cache-resident before they're actually used. 3) SIMD: While we were discussing this routine in Discord, Paul noticed that the sample calculation was essentially performing a dot product of 2 4D vectors... which... GUESS WHAT. The SH4's FPU can do with a single instruction, FTRV, which is what "shz_dot8f()" provides an intrinsic around... The gainz were pretty substantial, despite having to convert back and forth between int16_t and floats. The new FP SIMD code can be enabled with "SH4_SIMD_GAINZ," otherwise the slow integer path is taken, so you can see the code difference. 4) Custom memcpy() routines: The builtin memcpy() routine that we're given in GCC15 from Newlib for the SuperH architecture is EXTREMELY slow... about as slow as copying byte-by-byte in ASM, so doing any sort of multi-byte loads and stores (provided adequately aligned buffers), even in C code, offers substantial gainz. Anyway, that's it for today! Stay tuned for more gainz!

Been up almost the entire night making big audio gainz on the SH4 CPU for the Sega Dreamcast port of Mario Kart 64! It took about 3 of us pitching ideas and optimizing together, but holy shit, the 200Mhz SH4 is keeping up 99% of the time doing all synthesis and mixing in SW! What you're seeing is the first hardware capture of Mario Kart 64 running on the Sega Dreamcast with working audio playback... and trust me, it was not easy to get here! First of all, all of the audio signal processing for synthesizing individual notes from sampling instruments then mixing the SFX channels and the BGM together into a single audio stream is being done completely in SW on the DC's 200Mhz SH4 CPU--while it was done in HW on the N64. It is also carrying the whole T&L load for rendering with extra overhead per draw call due to us using our OpenGL 1.1 driver for graphics (GLdc). You can currently see a teeny little bit of slowdown at the beginning of the race when all 8 karts are bunched together, emitting their own SFX, which all has to get mixed in SW, bogging down the CPU... but don't worry, plenty of gainz left! On the left is a very interesting routine which proved to be incredibly gainzy when accelerated... So lets jump into what we did to this "aResampleImpl()" routine! 1) Compiler Optimizations: Everything is compiled with -Os by default to save RAM, because jnmartin is preloading almost everything up-front; however, we've created a "hot file" listing within the Makefile which allows us to build specific perf-critical translation units at with the -O3 optimization flag. 2) Manually managing the data cache: notice how many prefetches and barriers are in this routine in order to phenangle GCC's codegen to be somewhat similar to the ordering we've done things in C. Additionally, I've gone through hell in Compiler Explorer to ensure that all of the buffers used here can be prefetched in a timely manner, so that they're cache-resident before they're actually used. 3) SIMD: While we were discussing this routine in Discord, Paul noticed that the sample calculation was essentially performing a dot product of 2 4D vectors... which... GUESS WHAT. The SH4's FPU can do with a single instruction, FTRV, which is what "shz_dot8f()" provides an intrinsic around... The gainz were pretty substantial, despite having to convert back and forth between int16_t and floats. The new FP SIMD code can be enabled with "SH4_SIMD_GAINZ," otherwise the slow integer path is taken, so you can see the code difference. 4) Custom memcpy() routines: The builtin memcpy() routine that we're given in GCC15 from Newlib for the SuperH architecture is EXTREMELY slow... about as slow as copying byte-by-byte in ASM, so doing any sort of multi-byte loads and stores (provided adequately aligned buffers), even in C code, offers substantial gainz. Anyway, that's it for today! Stay tuned for more gainz!

Falco Girgis

15,547 views • 11 months ago

JNMARTIN HAS BROUGHT US CHRISTMAS EARLY THIS YEAR!!! His port of Star Fox 64 to the Sega Dreamcast is officially complete and was just released! Here's 9+ minutes of spliced direct hardware captures, featuring footage from every mission running on an actual physical DC at 480p! I have to say, the game feels incredibly smooth and responsive on the DC and controls extremely well. Also... as you can see, at twice the resolution with progressive scan, she looks gorgeous even with my cheap-ass HDMI cables and USB capture card. While jnmartin had the game up and running on DC within (literally) 2 days, there was an enormous amount of time and energy invested into faithfully recreating the experience graphically, implementing various bugfixes, and hunting for performance gainz... the man has never been satisfied with anything short of amazing with his ports, and it really shows. Like his Mario Kart 64 port, Star Fox 64 is also using my SH4ZAM library to hardware accelerate the math and linear algebra routines for DC; however, unlike last time, he's gotten so good at performance gainz that I barely did anything at all on that side, other than writing a few little inline SH4 ASM routines to cover some operations that I didn't already accelerate within the API... Suffice to say, though, that everything from the vertex TnL pipeline, to audio decoding, to gameplay-related trigonometry routines has been optimized for the SH4's FPU... jnmartin even got to bust out the SH4's MMU to accelerate the translation of of the segmented address scheme used by the game on N64 (which was apparently some suggested memory management model in the N64 docs) into the DC's virtual address space--which previously had to be done in software... So even more gainz! Sorry, though... but pretty sure this is why the game won't work in the Flycast emulator currently... whoops! 🤣 Shout-out to darcagent for contributing DREAMCAST RUMBLE PACK SUPPORT (among other things) to the release. Rumble support has historically been a pain-point within our KallistiOS homebrew DC SDK, as many 3rd party rumble packs are non-compliant and either do what they want with certain rumble commands or screw up the entire maple bus when they receive something they have decided not to fully implement... Great job getting that shit sorted out and tested with so many packs. All of my exotic (and cheapo) 3rd party rumble devices that I was able to test with seemed to work great! Finally, lets give SonicDcer a round of applause for being the lead dude behind the original N64 decompilation--as it was his original work that allowed for any of this to even be possible. He also continued to offer support and advice throughout the entire porting process, like a total chad. Here's the link to the official GitHub repo with instructions for building a Dreamcast image from a StarFox N64 ROM:

JNMARTIN HAS BROUGHT US CHRISTMAS EARLY THIS YEAR!!! His port of Star Fox 64 to the Sega Dreamcast is officially complete and was just released! Here's 9+ minutes of spliced direct hardware captures, featuring footage from every mission running on an actual physical DC at 480p! I have to say, the game feels incredibly smooth and responsive on the DC and controls extremely well. Also... as you can see, at twice the resolution with progressive scan, she looks gorgeous even with my cheap-ass HDMI cables and USB capture card. While jnmartin had the game up and running on DC within (literally) 2 days, there was an enormous amount of time and energy invested into faithfully recreating the experience graphically, implementing various bugfixes, and hunting for performance gainz... the man has never been satisfied with anything short of amazing with his ports, and it really shows. Like his Mario Kart 64 port, Star Fox 64 is also using my SH4ZAM library to hardware accelerate the math and linear algebra routines for DC; however, unlike last time, he's gotten so good at performance gainz that I barely did anything at all on that side, other than writing a few little inline SH4 ASM routines to cover some operations that I didn't already accelerate within the API... Suffice to say, though, that everything from the vertex TnL pipeline, to audio decoding, to gameplay-related trigonometry routines has been optimized for the SH4's FPU... jnmartin even got to bust out the SH4's MMU to accelerate the translation of of the segmented address scheme used by the game on N64 (which was apparently some suggested memory management model in the N64 docs) into the DC's virtual address space--which previously had to be done in software... So even more gainz! Sorry, though... but pretty sure this is why the game won't work in the Flycast emulator currently... whoops! 🤣 Shout-out to darcagent for contributing DREAMCAST RUMBLE PACK SUPPORT (among other things) to the release. Rumble support has historically been a pain-point within our KallistiOS homebrew DC SDK, as many 3rd party rumble packs are non-compliant and either do what they want with certain rumble commands or screw up the entire maple bus when they receive something they have decided not to fully implement... Great job getting that shit sorted out and tested with so many packs. All of my exotic (and cheapo) 3rd party rumble devices that I was able to test with seemed to work great! Finally, lets give SonicDcer a round of applause for being the lead dude behind the original N64 decompilation--as it was his original work that allowed for any of this to even be possible. He also continued to offer support and advice throughout the entire porting process, like a total chad. Here's the link to the official GitHub repo with instructions for building a Dreamcast image from a StarFox N64 ROM:

Falco Girgis

30,965 views • 7 months ago

Sonic Mania Plus for the Sega Dreamcast finally has audio! Here's a 2 minute direct hardware capture of me playing the latest build of Michael Fadely's port on my actual DC to hype up the Blue Blur's epic comeback to a Sega console... where he has always belonged!

Sonic Mania Plus for the Sega Dreamcast finally has audio! Here's a 2 minute direct hardware capture of me playing the latest build of Michael Fadely's port on my actual DC to hype up the Blue Blur's epic comeback to a Sega console... where he has always belonged!

Falco Girgis

168,686 views • 5 months ago

SHE'S DONE!!! Mario Kart 64 for the Sega Dreamcast is officially ready for public consumption, so here's a full 6+ minute video of gameplay, captured straight from my actual DC! Jnmartin has done it again! The footage you are watching shows every GP course in the game, including multiplayer footage as well. Yes, you can also save and load ghost files from the VMU! As this is our first release, I'm sure you will run into a minor bug here or there, especially given neither one of us could stress test 4 player very effectively using our hands and feet to drive... So be sure to open tickets for any minor issues you find... assuming you're playing on REAL HARDWARE. I can already tell you right now, emulators are having issues with this one! This was my first time getting to directly contribute to a jnmartin N64 port, and it was an absolute honor for me to be involved with his incredible work. There is nobody else who I have ever met with the cross-architecture knowledge of BOTH the Sega Dreamcast and Nintendo 64, combined with the raw grit, tenacity, and attention to detail required to pull this off and do the source material justice. Not only did I get to take my SH4ZAM library for DC math gainz out for a ride with MK64, but I also brought some new routines back from MK64 so everyone can use them! Finally, I got to be involved in laying the foundation for future jnmartin N64 ports, now that we have an optimized, accelerated audio and video back-end for various libultra functionality, including Fast3D. You can already see how much this has benefited future work based on how quickly jnmartin was able to get StarFox 64 up and running on DC... The man doesn't sleep, no. lol. I just wanted to thank everyone so much for the continued enthusiasm and support behind these ports. The support for our work and the Sega Dreamcast means the world to us! Thanks for helping to keep the dream alive! For instructions on how to build yourself a burnable CDI image or a DreamShell ISO for either your DC's SD card or IDE drive, please follow the README on the repository: NOTE: Windows users will need DreamSDK to build. My last-minute build fixes for DreamSDK are in this WIP branch here, which will probably be merged into the main branch tomorrow when jnmartin wakes up:

SHE'S DONE!!! Mario Kart 64 for the Sega Dreamcast is officially ready for public consumption, so here's a full 6+ minute video of gameplay, captured straight from my actual DC! Jnmartin has done it again! The footage you are watching shows every GP course in the game, including multiplayer footage as well. Yes, you can also save and load ghost files from the VMU! As this is our first release, I'm sure you will run into a minor bug here or there, especially given neither one of us could stress test 4 player very effectively using our hands and feet to drive... So be sure to open tickets for any minor issues you find... assuming you're playing on REAL HARDWARE. I can already tell you right now, emulators are having issues with this one! This was my first time getting to directly contribute to a jnmartin N64 port, and it was an absolute honor for me to be involved with his incredible work. There is nobody else who I have ever met with the cross-architecture knowledge of BOTH the Sega Dreamcast and Nintendo 64, combined with the raw grit, tenacity, and attention to detail required to pull this off and do the source material justice. Not only did I get to take my SH4ZAM library for DC math gainz out for a ride with MK64, but I also brought some new routines back from MK64 so everyone can use them! Finally, I got to be involved in laying the foundation for future jnmartin N64 ports, now that we have an optimized, accelerated audio and video back-end for various libultra functionality, including Fast3D. You can already see how much this has benefited future work based on how quickly jnmartin was able to get StarFox 64 up and running on DC... The man doesn't sleep, no. lol. I just wanted to thank everyone so much for the continued enthusiasm and support behind these ports. The support for our work and the Sega Dreamcast means the world to us! Thanks for helping to keep the dream alive! For instructions on how to build yourself a burnable CDI image or a DreamShell ISO for either your DC's SD card or IDE drive, please follow the README on the repository: NOTE: Windows users will need DreamSDK to build. My last-minute build fixes for DreamSDK are in this WIP branch here, which will probably be merged into the main branch tomorrow when jnmartin wakes up:

Falco Girgis

63,174 views • 11 months ago

I have something very special to share today! This is a hardware capture of maximqad's port of the Xash3D engine--which is compatible with the Half-Life engine--running on the Sega Dreamcast... ONLINE! Keep in mind this is EXTREMELY early in the days of the port, with no DC-specific graphics optimizations or hardware accelerated math routines yet, so performance still has a lot of room to drastically improve. Audio was literally just barely moved to the SPU for the first time just the other day too, so this is still all very incredibly new... ...but here it is! The engine that wouldn't even run without being on an emulator that also needed to emulate the extended 32MB RAM modification... now running on a stock Sega Dreamcast with online multiplayer connectivity and mouse and keyboard support! Fantastic work from maximqad! I really believe as this engine matures, it will be an incredibly powerful tool for Dreamcast developers and will potentially bring a lot of new software to the platform in the form of Half-Life engine mods!

I have something very special to share today! This is a hardware capture of maximqad's port of the Xash3D engine--which is compatible with the Half-Life engine--running on the Sega Dreamcast... ONLINE! Keep in mind this is EXTREMELY early in the days of the port, with no DC-specific graphics optimizations or hardware accelerated math routines yet, so performance still has a lot of room to drastically improve. Audio was literally just barely moved to the SPU for the first time just the other day too, so this is still all very incredibly new... ...but here it is! The engine that wouldn't even run without being on an emulator that also needed to emulate the extended 32MB RAM modification... now running on a stock Sega Dreamcast with online multiplayer connectivity and mouse and keyboard support! Fantastic work from maximqad! I really believe as this engine matures, it will be an incredibly powerful tool for Dreamcast developers and will potentially bring a lot of new software to the platform in the form of Half-Life engine mods!

Falco Girgis

17,012 views • 1 year ago

OKAY, FIIIINE! It's true! The Legend of Zelda: Ocarina of Time is now actively being ported to the Sega Dreamcast!!!! Here's a direct hardware capture I LITERALLY just barely took of me testing out a bunch of optimizations I'm making to the matrix routines using my SH4 accelerated SH4ZAM library. This port was started and is currently being led by a total chad who was always joking that he'd do the legwork to get the port started for jnmartin, who was never particularly interested in OoT, despite the desperate pleas from the fans... Mr. Chad knew that jnmartin wouldn't be able to resist jumping in and helping with the port once the initial work was done... aaaand he was 100% right! 🤣 While Mr. Chad, OoT leader prefers to remain anonymous (so people can't bitch at him over bugs or pressure him to hurry up), he and jnmartin have been working their asses off to get the port this far... to the point of the entire game being mostly playable with occasional graphical glitches or crashes here and there... Oh... and don't mind me... I'm late to the party, but I figured I'd jump in and do my thing, SH4ZAM-ing up and optimizing the vectors, matrices and math, especially for the more complex animations and skinning in this port!

OKAY, FIIIINE! It's true! The Legend of Zelda: Ocarina of Time is now actively being ported to the Sega Dreamcast!!!! Here's a direct hardware capture I LITERALLY just barely took of me testing out a bunch of optimizations I'm making to the matrix routines using my SH4 accelerated SH4ZAM library. This port was started and is currently being led by a total chad who was always joking that he'd do the legwork to get the port started for jnmartin, who was never particularly interested in OoT, despite the desperate pleas from the fans... Mr. Chad knew that jnmartin wouldn't be able to resist jumping in and helping with the port once the initial work was done... aaaand he was 100% right! 🤣 While Mr. Chad, OoT leader prefers to remain anonymous (so people can't bitch at him over bugs or pressure him to hurry up), he and jnmartin have been working their asses off to get the port this far... to the point of the entire game being mostly playable with occasional graphical glitches or crashes here and there... Oh... and don't mind me... I'm late to the party, but I figured I'd jump in and do my thing, SH4ZAM-ing up and optimizing the vectors, matrices and math, especially for the more complex animations and skinning in this port!

Falco Girgis

44,043 views • 3 months ago

Every day is a fantastic day to be playing Counterstrike... ON THE SEGA DREAMCAST! What you are seeing is a couple minutes of video featuring online play captured directly from the real hardware! This monumental feat of engineering is to be credited to developer, maximqad, who has successfully ported the Xash3D engine, which is Half-Life compatible, to the little white box, with its 200Mhz SH4 CPU and whopping 16MB of system memory. With the engine has come Half-Life, Counterstrike, and the possibility of many others on DC. Unlike the last time you saw these games, though, they're now glitch-free and are fully playable, with plenty of room for further optimizations left! Speaking of gainz, one of the most interesting battle stories from this project has got to be maximqad offloading some of the engine's allocations for its BSP from system memory onto video memory, which the Dreamcast tends to have an abundance of, at 8MB, with support for a fantastic VQ hardware compression format. For more footage from this play session, check out SWAT's full capture here:

Every day is a fantastic day to be playing Counterstrike... ON THE SEGA DREAMCAST! What you are seeing is a couple minutes of video featuring online play captured directly from the real hardware! This monumental feat of engineering is to be credited to developer, maximqad, who has successfully ported the Xash3D engine, which is Half-Life compatible, to the little white box, with its 200Mhz SH4 CPU and whopping 16MB of system memory. With the engine has come Half-Life, Counterstrike, and the possibility of many others on DC. Unlike the last time you saw these games, though, they're now glitch-free and are fully playable, with plenty of room for further optimizations left! Speaking of gainz, one of the most interesting battle stories from this project has got to be maximqad offloading some of the engine's allocations for its BSP from system memory onto video memory, which the Dreamcast tends to have an abundance of, at 8MB, with support for a fantastic VQ hardware compression format. For more footage from this play session, check out SWAT's full capture here:

Falco Girgis

36,750 views • 1 year ago

FINALLY time for the big announcement everyone has been begging and waiting for... Here's a VERY EARLY direct hardware capture of Mario Kart 64... RUNNING ON THE SEGA DREAMCAST, of course! This game was literally just BARELY decompiled the other day, with a codebase that is still quite married to the Nintendo 64 platform... but this didn't stop jnmartin: the dark coding wizard who brought us a dynamically lit and bump mapped Doom 64 and Wipeout running at >100FPS on the DC! What you're seeing is the insane progress made by one man in just 3 weeks. As is to be expected, there are all kinds of visual glitches and rendering artifacts, the framerate is all over the place, and there's no audio yet... which is totally typical of any ambitious DC port in the early stages. The DC build wouldn't even get past the menu screen without crashing or running out of RAM until just a few DAYS ago, yet here it is, every level playable WITH multiplayer support already on the DC! Even in this early stage, you can already see the game benefiting from the PVR's crisp 480p output... Each players' little viewport window in 4 player mode is the same resolution as the entire screen was on the N64! Stay tuned for future updates as jnmartin continues his work to bring this classic to our little white box of Dreams!

FINALLY time for the big announcement everyone has been begging and waiting for... Here's a VERY EARLY direct hardware capture of Mario Kart 64... RUNNING ON THE SEGA DREAMCAST, of course! This game was literally just BARELY decompiled the other day, with a codebase that is still quite married to the Nintendo 64 platform... but this didn't stop jnmartin: the dark coding wizard who brought us a dynamically lit and bump mapped Doom 64 and Wipeout running at >100FPS on the DC! What you're seeing is the insane progress made by one man in just 3 weeks. As is to be expected, there are all kinds of visual glitches and rendering artifacts, the framerate is all over the place, and there's no audio yet... which is totally typical of any ambitious DC port in the early stages. The DC build wouldn't even get past the menu screen without crashing or running out of RAM until just a few DAYS ago, yet here it is, every level playable WITH multiplayer support already on the DC! Even in this early stage, you can already see the game benefiting from the PVR's crisp 480p output... Each players' little viewport window in 4 player mode is the same resolution as the entire screen was on the N64! Stay tuned for future updates as jnmartin continues his work to bring this classic to our little white box of Dreams!

Falco Girgis

55,523 views • 1 year ago

Sooo... How's our port of Sonic Mania to the Sega Dreamcast coming along!? SHE'S ALMOST DONE! We're getting ready for release!!! As you can see from these direct hardware captures, the game looks and runs amazingly on the DC! Multiple beta testers have now cleared the game on both Mania and Encore modes! Jnmartin worked his butt off finishing up the remaining effects, Michael Fadely is working on the final bit of polish, such as making sure the menu button icons show Dreamcast controller graphics, and I just opened a PR to put the gameplay code on the latest SH4ZAM commit... STAND BY FOR THE BLUE BLUR'S EPIC RETURN TO THE SEGA DREAMCAST!

Sooo... How's our port of Sonic Mania to the Sega Dreamcast coming along!? SHE'S ALMOST DONE! We're getting ready for release!!! As you can see from these direct hardware captures, the game looks and runs amazingly on the DC! Multiple beta testers have now cleared the game on both Mania and Encore modes! Jnmartin worked his butt off finishing up the remaining effects, Michael Fadely is working on the final bit of polish, such as making sure the menu button icons show Dreamcast controller graphics, and I just opened a PR to put the gameplay code on the latest SH4ZAM commit... STAND BY FOR THE BLUE BLUR'S EPIC RETURN TO THE SEGA DREAMCAST!

Falco Girgis

139,608 views • 17 days ago

What you are seeing here is a totally revamped and improved version of a Dreamcast homebrew classic: the Caves tech demo, captured directly from a Sega Dreamcast. FreakDave's original demo already impressed the hell out of me when I first saw it several years ago, getting back into DC development after a several-year hiatus... but this new demo is absolutely INCREDIBLE stuff. It's powered by FreakDave's FDV engine, and now features vertex-based ambient occlusion, light baking, approximated global illumination, fog, and crazy water effects in addition to the dynamic lighting of the original all running at higher FPS! ...and now I can brag about the fact that he's using my SH4ZAM linear algebra library for the DC's SH4 CPU to accelerate all of the math behind the effects! Makes me proud AF! Great work, my dude! Check out the demo here:

What you are seeing here is a totally revamped and improved version of a Dreamcast homebrew classic: the Caves tech demo, captured directly from a Sega Dreamcast. FreakDave's original demo already impressed the hell out of me when I first saw it several years ago, getting back into DC development after a several-year hiatus... but this new demo is absolutely INCREDIBLE stuff. It's powered by FreakDave's FDV engine, and now features vertex-based ambient occlusion, light baking, approximated global illumination, fog, and crazy water effects in addition to the dynamic lighting of the original all running at higher FPS! ...and now I can brag about the fact that he's using my SH4ZAM linear algebra library for the DC's SH4 CPU to accelerate all of the math behind the effects! Makes me proud AF! Great work, my dude! Check out the demo here:

Falco Girgis

15,701 views • 3 months ago