Astro City with Groovymame PC vs FPGA Mister?

[dre1]

I play shoot 'em ups on a restored Astro City cabinet equipped with a Nanao CRT monitor. The setup is connected to a PC with a CRT emulation driver running Groovymame (Attract Mode).

My question:
Would a MiSTer FPGA be better than the MAME PC? In what ways?

[Firehawke]

This is going to get a bit preachy. I apologize in advance, it just needs to be detailed outright.

The MiSTer is not *inherently* more accurate (FPGA is, despite what Analogue tells you, still emulation)-- the quality of the FPGA implementation is something that can vary. If you were to port Nesticle to FPGA, it's not going to be inherently any more accurate than Nesticle was on a Win9X/MS-DOS machine back in the day.

That said, the MiSTer project does aim for good accuracy where possible, and many of the inaccurate things that have been found while tracing PCBs have been corrected and backported back into MAME. Cores outside of N64 (where corners had to be cut) tend to be pretty solid. MAME isn't perfect, but a lot of the games are pretty solid there too. Where you hit problems are things like CPS-2 where bus contention and wait states aren't implemented and so speeds tend to be an approximation and not totally accurate. This is, for instance, a known headache to the Super Street Fighter 2 Turbo community.

Another major point of note is that the FPGA doesn't have an OS that can interrupt the game. A lot of the latency that you see in MAME (outside of misconfiguration, not having a VRR low-latency monitor, etc) comes from the OS. MiSTer won't have to deal with that additional source of headaches.

Me? I have a MISTer and I have a PC. I use both depending on what I'm playing and whether it's even available on PC (I don't expect to ever see CV1000 or NAOMI on MiSTer, for instance) and whether the existing MAME implementation is sufficient.

YMMV.

[spmbx]

A mister would imho run a bit more stable with less chance of something in windows or whatever suddenly going to shit and messing up the system. Also boots faster and in general a bit less of a headache

[emphatic]

I'm currently using a RaspberryPi 5 with ReplayOS on a CRT TV using a RGB-Pi and it's fast, simple and very cabinet friendly. However, I'm not sure how you can use it in a JAMMA setup. The ReplayOS has support for most arcade systems, including CV-1000 CAVE games. I guess the newly added corrected slowdowns for those will be implemented soon. But you can even play the NAOMI games without problems if you're OK running them in 15kHz.

[PC Engine Fan X!]

I use a South Korean based Crown Arcade produced "Raspberry Pi to Jamma" pcb with an overclocked Raspberry Pi 4 plus RGB-Pi OS4 front end and Final Burn Neo emulation to play the Cave CV-1000-based DoDonpachi Sai-Dai-Ou-Jou stg in proper tate with true 15.7kHz low-res support from the get-go. The on-board heavy-duty cooling fan located on the underside of the pcb itself is more than adequate enough for an overclocked R-Pi 4 (that remains cool to the touch when in operation) if it's used for "extended marathon gaming sessions" indeed.

Is considered/regarded as the cheapest way to play DDP-SDOJ on a low-res 15.7kHz candy cab setup "without breaking the bank" nowadays + proper scanline support is already included as a bonus as well -- how cool is that? It doesn't get any better than that, folks. Running the Raspberry Pi to Jamma pcb with a dedicated portable supergun + pro-grade CRT-based RGB gaming monitor setup are equally at home just as well.

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Here's the listing for a Crown Arcade Raspberry Pi to Jamma pcb: https://www.ebay.com/itm/204368012484?i ... SwMzhlARs0
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PC Engine Fan X! ^_~

[dre1]

you can even play the NAOMI games without problems

I play them on Flycast Emulator. PS2 on Nether2xs, PSX on Retroarch and so on..

[ChurchOfSolipsism]

I play arcade games on a CRT via Pi4 + Recalbox + RGB Dual which claims to give you every game with the correct resolution and frequency and puts out an RGB signal via scart cable, and personally I have never noticed anything off. There's also the RGB jamma, which lets you connect your recalbox pi to a jamma setup:

https://www.recalbox.com/recalbox-rgb-jamma/

Haven't tried it since I don't own a jamma cab anymore, but if it's anywhere near as good as the RGB Dual, it's absolutely brilliant.

[Bassa-Bassa]

The problem in my eyes with RGB Pi/Replay OS is that the author doesn't say how he achieves low latency nor likes to give technical explanations, and then, you depend on both, his updates and Retro Arch's.

Groovymame depends on a single guy's work, but he hasn't failed for more than decade now and all his developments are openly explained, so you can understand how his frame delay works and why it's the optimal solution for computers including Linux-based like Raspberry Pi developments. Also, it will let you control picture geometry and framerate aspects like no other solution.

I agree that a Mister+Groovymame setup combo is the way to go. Mame has it all for 15khz (and Windows itself via Emudriver (required for Groovymame) will let you play lots of Windows games which run better on a 15khz setup), but many things just run more accurately on Mister, like the aforementioned Capcom games, and it's also much easier to get rid of audio lag. Moreover, this combo will let you use Groovymister, which would be the ultimate solution for Groovymame, as any video hindrance from the graphics card is automatically solved.

[Sumez]

The MiSTer is not *inherently* more accurate (FPGA is, despite what Analogue tells you, still emulation)-- the quality of the FPGA implementation is something that can vary. If you were to port Nesticle to FPGA, it's not going to be inherently any more accurate than Nesticle was on a Win9X/MS-DOS machine back in the day.

Even though I agree with the core argument here - that FPGA emulation isn't *inherently* more accurate, I think the idea of "porting a software emulator to hardware emulation" is a little nonsensical in this context.
Of course, in the case of Nesticle, I do think a few of its shortcomings probably come down to a certain lack of understanding of the NES at the time, but more often the limitations you see in software emulation, outside of the OS layer that you already mentioned, is that trying to achieve in functional programming what integrated circuits do through logic gates isn't always as simple as just telling the code how it works. You're gonna have to cut corners.

The NES at this point is a fully understood system, but all software emulators will always have to come with some caveats when implementing it. There's always going to be *SOME* point where instead of directly emulating the hardware behavior, you're gonna have to just tell the computer "ok when these things happen, the system does this". At what point you end up doing that is the difference between "high level" and "low level" emulation. At the lowest possible level you'd be emulating every single transistor in the hardware, and your software emulator would be 100% accurate, but it wouldn't be reasonable to run it like that on an actual computer.
Funny enough, literally the same person who made Nesticle actually made an NES emulator that does exactly this. And it takes several minutes just to draw a single frame: https://github.com/iaddis/metalnes

FPGA emulation allows emulation on a logic gate level, which is much lower than any software emulator could reasonably do. The way it works is just completely different.
So while an FPGA emulator isn't necessarily more accurate because it's FPGA, it definitely potentially can be. And it's not unreasable to expect that it is


Source: I also made an NES emulator

[Firehawke]

It's really not that nonsensical when you consider that several of the edge-case cores (e.g. N64) are already a hybrid of HLE and LLE. At that point, the HLE components are closer to ported PC emulation code than actual representations of the original hardware behavior.

[Sumez]

I'd agree with that absolutely

[PC Engine Fan X!]

I play shoot 'em ups on a restored Astro City cabinet equipped with a Nanao CRT monitor. The setup is connected to a PC with a CRT emulation driver running Groovymame (Attract Mode).

My question:
Would a MiSTer FPGA be better than the MAME PC? In what ways?

For dre1,

Could you tell us what PC specs you're using with your Mame emulation rig? And what GPU are you using to output properly in 15.7kHz format (is the output cable a "VGA to Scart" cable output)?

I do see that the AMD Radeon HD5450 with 1GB DDR3 setup GPU (with it's mounted huge heatsink cooling apparatus in lieu of a traditional cooling fan setup) is a recommended one for outputting in 15.7kHz via it's VGA output port (even though it has three outputs: VGA, DVI-D {and not DVI-A} and HDMI).

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It's well-known that the Ultimarc based "Arcade VGA" GPU (which does output in 15.7khz low-res format at 320 x 240p) is nothing more than a repurposed/rebranded/restickered AMD Radeon HD5450 GPU as it is -- I did not know this until very recently.
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PC Engine Fan X! ^_~