Sega Virtua Processor (SVP) Homebrew on the Sega Genesis & Mega Drive

[@captainrayo]

Thanks for documenting Javi's effort so brilliantly. I'm very proud of being Javi's brother. Written with love from Cádiz, Spain XD

[@RetroSegaDev]

You're his brother 😄 He's done a grand job!

[@TaiyouHKabra]

Awww. Matt, he taught me Basic language on our MSX computer when I was 6 years old (my first contact with technology), and he also had the idea for my family to get me Virtua Racing as a present for Xmas 1994... so he did his part on this too :D

[@my80chevettes]

Greetings from Cadiz Ohio 👍

[@datagod]

What a time to be alive. We are able to crack open the devices of wonder from our childhood and discover how they work. Great video!!

[@gianlucag6976]

See other games with SVP was my dream back in the day. I hope we will see something interesting in the future, maybe a VF port.

[@maroon9273]

Great what if scenario if hackers also ported star war arcade, doom and daytona usa and all of the flat shading 32x games to the svp. I wish sega would've continued supporting the svp or started releasing enhancement chips and cancelling 32x add-on (continue the project as a 32-bit handheld console).

[@unverifiedbiotic]

@@maroon9273 SVP was way less powerful than the 32x, I don't think you'd get good results, VF1 would be unplayable in less than 25 FPS - probably why they dropped it when they did. Stupid, considering what Nintendo achieved with the even less powerful Super FX, but as history shows, SEGA had a lot of problems with their decision making. People who can do stuff like GBA Tomb Raider are few and very far between, and it took them years to accomplish - time is key in gamedev, and time is saved by high-level programming and skipping optimization.

[@billybob884]

very cool! love that there's so much activity in the sega homebrew community

[@QGmonkey64]

Thanks for covering this. I’ve wanted to build a game for the SVP some day and it’s great to see someone already started.

[@TaiyouHKabra]

I'd love to see that happening! All the tools described there are free to use and modify :)

[@SmallSpoonBrigade]

Any particular reason for it to be SVP rather than 32x?

[@QGmonkey64]

@@SmallSpoonBrigade I think it's an interesting chip that didn't get its chance to be fully used. I always wanted to see a VR cart turned into like a mini 32x/Sonic & Knuckles setup which was something they were considering. Bandai did something similar on the super famicom with the Sufami Turbo.

[@johnjay6370]

To this day I think Sega should have released a snap on SVP chip, and never release the 32x. The SVP chip could have cost = $100 bucks with VR as a its come in game. Was the 32x faster? Yes, but honestly I think Sega could have made it work! It would have been a good way for Sega to compete with Nintendo Super FX chips. I also think it could have made a better version than the SNES doom... You do not need the higher color to make a Doom..

[@bjraleigh1439]

Call it the 'Virtua Drive' and bundle it with Virtua Racing and Virtua Fighter for $149 or the add on for $79, basically half the price of the 32x. I really think you can't have add ons costing more than the host console if you want mass adoption. I think you are right, they would have had a winner on their hands. I have no idea how the svp would translate when doing 2d stuff, but I gather it's sprite scaling would have been pretty strong. Doom would be an interesting one. The Genesis controller lacking shoulder buttons is a little concerning for a 1st person shooter.

[@SmallSpoonBrigade]

@@bjraleigh1439 I think they just wanted it out the door at that point. 32x and Saturn were released in such close proximity that it didn't much matter what they did.

[@felinefrequencies2179]

I'm a huge fan of Homebrew and love seeing advancements being discovered and shared allowing everyone involved to benefit from it! Great work!

[@RetroSegaDev]

You're welcome. I'm always trying to give focus on the good work that's going on.

[@adamdenardis5438]

Imagine more Virtua games on the Genesis? 😃

[@maroon9273]

Best time to do it. Sega dropped the ball by replacing it with another add-on called the 32x.

[@SmallSpoonBrigade]

@@maroon9273 Not really, Virtua Racing was extremely expensive for a Genesis cart due to the chip. The 32x was essentially what you get when you take the SVP and put it into a device that can have other games loaded into it. There's a bit more to it, but that's the idea. Rather than spending roughly $50 a game for the chip, you spent roughly triple that and got an adapter that worked across all the 32x games.

[@unverifiedbiotic]

SVP was supposed to be a lock on cart and it would have been a way better idea than the 32x - production and end user cost were much lower. This was much faster than super fx, and that moved millions of games during the snes's final years.

[@Jeancarlo842]

O mega drive (Genesis) fez parte da minha vida, por isso estou desenvolvendo um jogo para esse console hj em dia

[@olivieribassi647]

Que legal , desejo sucesso. Viva a comunidade ativa do mega !

[@maxrichards5925]

I am so excited to see this. This is incredible!

[@gumpyflyale2542]

Is doom possible with the SVP chip?

[@fahrenheit1391]

Possible

[@igorkrugly4842]

A wonderful piece of hardware!

[@jimmyf2618]

Omg I always dreamed what could be done with the SVP chip woooowwww

[@RetroSegaDev]

We just have to hope someone uses what Javi has come up with 😁

[@jimmyf2618]

@@RetroSegaDev my dream is to see a Sega or Sega svp or games with glorious 32 768 colors

[@maroon9273]

@@jimmyf2618 it will happen once the 32x hardware is added to the everdrive pro and sd card of the 32x/32x cd

[@jbmaru]

This is awesome, kudos to Javi and thanks for this video.

[@GadgetUK164]

Wonderful video, and amazing work by Javi!!!!

[@RetroSegaDev]

Thanks! Javi's work has been top notch just need some folk to start taking advantage of it!

[@itsasecrettoeverybody]

Amazing work so far. Thanks for covering it.

[@RetroSegaDev]

Very welcome!

[@Pai3000]

And I thought the video would be too short... Great job, man

[@RetroSegaDev]

Not all my videos are tiny 😅

[@WilfredBrimleyGaming]

Always wondered about the SVP, seemed like it had potential

[@maroon9273]

More potential than the 32x and 32xcd

[@FrozenDrone12]

​@@maroon9273 Sega SVP is basically what happens if at the time Sega is just keep unleashing the potential of the main console (Genesis/ Mega Drive) rather then releasing many of useless add on that ruining their market themselves

[@gaving.griffon2703]

I could imagine sega CD svp games as well.

[@MoreFunMakingIt]

Brilliant video! Looks at the animation! You must put so much work into these.

[@RetroSegaDev]

Sure do 😂 I need to be getting into DaVinci Resolve to cut it down!

[@maroon9273]

Thanks for covering the SVP chip. Hopefully we will have a homebrew port of them in the future. Especially virtua fighter, doom, star wars arcade and Daytona USA being ported to the genesis as SVP titles. Where we could see what if scenario if sega didn't give up on the svp and cancelled the 32x. Can you also cover snes enhancement chips, nec pcfx cancelled 3d accelerator add-on and Saturn accelerator 3d enhancement chip for vf3.

[@RetroSegaDev]

You need to visit Sharopolis who's covered some of the SNES chips! kzbin.info

[@maroon9273]

@@RetroSegaDev thanks

[@Animated__Freak]

I would love to see a port of Doom for the SVP just to compare it with the one on the FX chip in the super nintendo.

[@RetroSegaDev]

The lack of colour is the issue. The SNES had an advantage 😔

[@Animated__Freak]

@@RetroSegaDev Yes but I still want to see it.

[@maroon9273]

@@RetroSegaDev maybe they can hack the megacolor player patch to increase the color count on the genesis.

[@Imgema]

@@RetroSegaDev Yeah but the SVP was more powerful than the FX2 so the port would probably have faster frame rate or better graphics like textures on floors and ceilings.

[@RetroSegaDev]

Nope it wouldn't. Frame rate is locked to the DMA transfer rate to VRAM!

[@jesusrelinqueperez6878]

That's an awesome video, so inspirational and instructive! Great job!

[@RetroSegaDev]

Thank you I'm glad you enjoyed it!

[@dreamcastfan]

It’s cool to see the SVP getting some love, normally the only 3D chip that gets attention is the SuperFX. I wonder if this could lead to overclocking the SVP chip, and whether it could make any difference to VR’s performance? I guess it would probably be like overclocking the SuperFX where games run faster rather than smoother. I’d love to see Virtua Fighter or Star Wars Arcade on it, even though we did get them on the 32X.

[@TaiyouHKabra]

In the case of Virtua Racing it wouldn't matter much. The bottleneck in the SVP case is the DMA speed of the Mega Drive, which limits how much graphics data can the MD pull from the external DRAM in the cartridge. That's why instruction timing accuracy wasn't required to emulate VR in the first place, as basically the SVP code is running when the MD requests it to do stuff. Also the DSP inside the SVP has a max clock speed of 25MHz, beyond that probably the system would become really unstable (and both the SVP and the MD sides are accessing the same ROM chip, which makes the timing of the SVP to be really important, as code requests from both sides are being interleaved so they don't block each other). But I'm sure more can be done with the SVP than what VR did, specially if effort is placed on the MD side of things to increase the bandwidth of data that can be pulled from the cartridge memory.

[@RetroSegaDev]

Using the sky box background certainly saved on tiles. I don't suppose you know if the SVP was optimised to remove duplicate tile patterns? I know the ASIC on the MCD wasn't

[@TaiyouHKabra]

Besides some circuitry to translate bitmap graphics into tilesets (not used by VR), there's nothing in the SVP to deal with tiles. It's all software rendering, only that the DSP runs way faster than the MD and can multiply 16 bit numbers quite fast. But that's about it. At the end of things you need to translate graphics from DRAM to the MD's VDP to be shown by the MD, that's unavoidable, so the DMA is the issue here. That's probably the reason they designed the 32X to have its own display output, so they didn't need to rely on the MD's DMA to output rendered graphics.

[@dreamcastfan]

@@TaiyouHKabra Fascinating, thank you! I’ve always wondered about this, I can’t wait to see what people do with the SVP in the future.

[@maroon9273]

@@TaiyouHKabra would programmers have the same bottleneck problems as the svp and sega cd if they used RISC 32-bit CPU or Coprocessor enhancement chip with same amount of ram as the svp or 32x? I know the everdrive pro (fpga tech) was able to port doom 1 and 2 to genesis with no problem using the mega drive hardware to render the graphics.

[@deaniepops1]

Brilliant can't wait for updates

[@marcw2604]

I hope Somebody Uses That SVP or 2 of those With 32x Sega Should Have put in a 32x Along With Both sh2 CPUs. If i had the know how to tie 2x svp or 3 to a Sega 32x hardware i could make Indy games on steam. Or home brew with a retro beefed up look.

[@ogsegasteve9430]

given how far the MegaGen has been pushed without any special chips, we can only wonder where SVP development will lead. Hope you have a few of these carts stored away for future use. I suspect the price of Virtua Racing carts will go up once this tech gets unlocked and people need dev boards and shells!

[@RetroSegaDev]

Possibly unless flash carts start providing proper SVP access!

[@TaiyouHKabra]

AFAIK Everdrive X7 has support for Virtua Racing, which albeit incomplete/unaccurate emulation (for some stuff that VR doesn't use, or instruction timings which probably aren't taken into account to emulate it)... would be a "comfortable" way to develop something for the SVP now without having to modify a Virtua Racing copy. I'm working on a SVP emulator for debugging/development purposes on my free time (so that would take some time to be usable), that hopefully helps with that too.

[@seamusoblainn]

What's the MegaGen project?

[@ogsegasteve9430]

@@seamusoblainn just the short fast way to say Mega Drive and Genesis. Some people call it one or the other so i just say #MegaGen because i collect for both.

[@seamusoblainn]

@@ogsegasteve9430 fair enough. When I searched for that term it came back with dentistry 👀. True sentiment of course. When you see what has been wrung out of the basic chipsets, it will be very interesting to see what can be achieved with real 3d functionality.

[@RetrogradeScene]

Great project! And great explanation love the visuals

[@RetroSegaDev]

Thank you 😁 glad you enjoyed it!

[@DaveVoyles]

Great work of breaking this all down

[@RetroSegaDev]

Thanks Dave! 😁

[@WilfredBrimleyGaming]

I wonder if virtua fighter 1 could be done on svp

[@RetroSegaDev]

It was planned! Along with Daytona 😁

[@RetroSegaDev]

It was planned! Along with Daytona 😁

[@DDRmails]

really great... i heard that there is star fox for SMD is WIP.... who knows - maybe oneday....

[@videogamemusicrenditionsby7625]

Got a copy of Virtual Racing for the MD today, for just €30... Am wondering how far could the SVP go, about its unexplored capabilities...

[@anticu4tro]

Bravo Javi!!

[@RetroSegaDev]

Yes, Bravo Javi! 🙂

[@Yesterzine]

Be interesting to see how emulators cope. Most are able to do Virtua Racing but that just means they've been written for that one game. When people start getting more creative with the chip it could all fall down.

[@RetroSegaDev]

Truth be told not even the flash carts simulate the SVP properly 😱

[@keiyakins]

I suspect the answer is close to "not at all". Unless some huge accuracy buff has gone all out, it's probably a relatively simple high-level emulation. Just figure out what the game is asking, do it however you can without regard for how the SVP works, and give it the answer.

[@adamdenardis5438]

Nothing a few updates couldn't fix. I mean look at how long it took for Kega Fusion.

[@baarrywilliams3606]

@@RetroSegaDev I wouls love to try this on my Mega everdrive Pro

[@deano72]

I wish it could have boosted existing 3d games on the megadrive.

[@ingusmant]

What are all those gatearrays for?

[@breaKdownINC]

What about the Mega Drive Flashcarts by Krikz and Terra Onion? They both use a FPGA reimplementation of the SVP, so that Virtua Racing works on those cards. Shouldn't people already be able to develop homebrew code for that chip then?🤔

[@RetroSegaDev]

Nope.... They're not timing accurate. They were developed purely to run Virtua Racing.

[@TaiyouHKabra]

Besides instruction timings, there are other bits that are not emulated (because Virtua Racing doesn't use it - makes sense). But I'd recommend for anyone that wants to start developing stuff with the SVP - just go ahead and try one of the software emulators that support it or the flashcarts that are available. You can always modify a copy of VR later to test it in "real hardware" when you have something up and running. Just for clarifying: I didn't create this boards specifically for developing games myself or anything, but to be able to research the chip "from the inside". I think that for 99% purposes, just sticking to those flashcarts or even the MiSTer MegaDrive core is enough to create a whole game.

[@maroon9273]

Including the everdrive pro?

[@RetroSegaDev]

Yup none are 💯 accurate

[@sonataonmymind]

Does the SVP also include the addition of 2 PWM channels? I see this information all the time on the internet

[@RetroSegaDev]

As far as I know this is a no. As the cart interface doesn't have anything connected to the audio lines

[@sonataonmymind]

@@RetroSegaDev Thanks for the answer :)

[@maroon9273]

@@RetroSegaDev so in order for the svp to have new audio channels, it will need mixing cable like the 32x or connecting pin to the genesis cart?

[@RetroSegaDev]

It's the cart lines for audio that aren't hooked up 🙂

[@maroon9273]

@@RetroSegaDev inside the svp chip or genesis hardware?

[@ripcase1990]

Imagine DOOM running on this thing.

[@DanielMcLaughlinMarriedMan]

great work

[@48hourrecordsteam45]

This is brilliant and this is what sega shoud have done to expand the genesis and not make that 32x. The svp chip was too powerful to just put it into one game and charge so much money for one title .!! Great idea killed by a very stupid decision.! Release the thing lock on stand alone cart like sonic and knuckles for $39.99 with 3 Virtua racing , virtua fighter, Star Wars arcade .for $49.99. And daytona usa coming soon - got Namco to port ridge race & tekken and got doom . 🙈 Made a next gen controller to release on the same day with the svp . Just the 6-button with a few tweaks . 1.an inch longer handle 2. 2 shoulder buttons 3.a lil analog stick next to the dpad 4.thicken & rounded the underbody to fit in the hand Simple 🤷🏾‍♂️ This would have saved sega so much going into the 32-bit gen

[@maroon9273]

Sega already had the 6 button genesis controller. Isn't it enough?

[@48hourrecordsteam45]

@@maroon9273I said modify the 6button controller, like a few edits/tweaks to release with the svp chip.? 1.Just made the handle a bit longer 2.Added to two shoulder buttons 3. Had a small analog stick next to the d-pad a little down the size of the ps vita .! I🤯

[@rafcast7197]

Brutal 🖤🖤🖤

[@FunBunChuck]

Make a custom cart with a Motorolla 68020 12 MHz chip and the GPU pulled from the CPS-2 (Capcom Play System 2 arcade board) with 128KB of additional Work RAM and 128KB of Video RAM for the GPU. Then pull a sound chip from another Sega Genesis console and add that to the cart with 64KB of Audio RAM. Create a game with about 48MB or 64MB of ROM storage. Using both the Genesis hardware and what you've added with the cartridge, you could make one hell of a game!

[@HelderB]

Awesome video.

[@RetroSegaDev]

Thank you! 😁

[@loganjorgensen]

Well very interesting. I wonder why Sega thought the SVP was ever going to be used by any other developer at that price, and why lock it away inside a single game? Could have been shaped like the Power Base Converter, could have been a Lock-On style cart like S&K so any game could pump through it.🤔

[@KaedeSmithOfTheKiller7]

Fascinating

[@legendsflashback]

Cool video

[@legendsflashback]

So you still have transformers movie 1986 Unicron galvatron fmv short scene from 2017 rom? You made a video in 2017 of it but sega-16 link dead.

[@RetroSegaDev]

Nope sorry

[@legendsflashback]

@@RetroSegaDev oh no 😢 so the file codec you used for that video is erases your hard drive? I think you made it in sdsk

[@RetroSegaDev]

No I don't have a working version anymore

[@BryanTruong]

Interesting!

[@RAVE_GHETTO_BLASTER]

👍

[@Eddies_Bra-att-ha-grejer]

What's the point of this? Isn't the 32x just a better version, and also part of a peripheral rather than inside a cartridge and hence easier to use for homebrew?

[@RetroSegaDev]

What's the point in anything? It's working towards an FPGA SVP homebrew. Examining the untapped potential of the SVP!

[@TaiyouHKabra]

The point of this was really about getting more detail about the chip itself (by being able to run stuff in the chip itself). That also opened the door for other people to use it for other means (e.g.: doing demos, games or whatever), but that's up to them! I just think it's fun :D

[@elessar5848]

Imagine a Formula one game. Like with the real circuits and names...

[@wookstv8647]

Good Luck.👩🏼‍🚒🧔🏼🏋🏽🤽🏼‍♀ Like # 455

[@SmokeTooMuch-e2s]

Would it be possible to Create Sega games utilizing the SVP, or would the 32X be more worthy of implementing into new Sega games? I feel creating games with the 32x-CD style would be more worthy, perhaps using the SVP as a Expansion to a 32X-CD game( That would mean creating games on something of a 32X-CD+SVP) Or more simply using a ARM-chip that would fit the Specs of the processing power of a 32X with 3 chips the two Hitachi + SVP capabilities while utilizing The SEGA CD implementations. (SVP 128kb DRAM -SVP 23Mhz) (SEGA CD For colors Sprites and Sound capabilities) while I know the SVP was originally going to be the other option to the 32X addon but why not add both? incorporate 32x/512kb with the SVP 128kb Sega/64kb of memory just pool the memory together~ So 640bk or ram, using the 2+1 32bit chips in addition with SEGA CD's 6 Mbit RAM (programs, pictures, and sounds), 128 kbit RAM (CD-ROM cache), 64 kbit RAM (backup memory) just an idea

[@RetroSegaDev]

Trying to combo things together is really just a waste of time they all fight for the memory bus. The 32x+CD doesn't offer you much more than better audio from the CD and more storage.