NESRGB board available now

[rolins]

So, any of these shipped yet?

Mine got shipped out yesterday. Crossing my fingers It'll arrive by next friday.

[BitFaced]

Smoky says: it's an NES. Play it on a CRT. Conversation over.

You can do that with RGB. Not with a HDMI NES or HDMI-modded N64 (The HDMI part at least).

Okay, here's what I received back from Marshall H. about the output res of the HDMI N64:
(I asked if it was 240p-only and he replied:)
"Nope, doesn't make sense as the N64 VI puts out 640x480 (or larger if you're PAL). This is to say the N64 internally interpolates the framebuffer as it outputs it.

An example would be Rampage which uses the oddball Williams arcade resolution, something like 430x240 or something. This comes out as 640x480 on the output of the RCP.

To make upscaling work between different sync rates (even ones that are very close but not quite) you need to have a framebuffer. That's why there is DDR ram on the converter board. The hardware is capable of 1080p without issue."
1080p-upscaled HDMI N64? Should be great!

The only question I still have then is whether or not you can just output in 480p and ignore the framebuffer, since it would add additional lag (I wouldn't be using HDMI anyway to be honest).

DON'T PEOPLE WANT A MIRACLE LIKE THIS?

[adimifus]

I personally have no interest in HDMI mods for any "classic" console (I'll say N64 generation and older). I am very sensitive to input lag, and any LCD/Plasma screen has enough lag to make it unenjoyable to play games on them, even with emulators already scaled to 1080p. No amount of work done to the video output can make it look as nice on an HDTV as a CRT, in my opinion. They were designed to be played on them, after all.
I'm not saying these HDMI mods are useless, since obviously not everybody has space for a CRT, and I'm sure others aren't as sensitive to the inherent lag as I am. They're just relatively useless to me.

Regarding the NESRGB, mine was shipped yesterday and I can't wait to get it. I had been closely following the UniversalPPU project for quite a while when I heard about this on assemblergames. I have experience with some of Tim's work (GGTV) and am very happy with how well it works, so I have no doubt this thing will be excellent.

[rCadeGaming]

You can do that with RGB. Not with a HDMI NES or HDMI-modded N64 (The HDMI part at least).

Right. I meant stop worrying about HDMI. At least in this thread.

[BitFaced]

I personally have no interest in HDMI mods for any "classic" console (I'll say N64 generation and older). I am very sensitive to input lag, and any LCD/Plasma screen has enough lag to make it unenjoyable to play games on them, even with emulators already scaled to 1080p. No amount of work done to the video output can make it look as nice on an HDTV as a CRT, in my opinion. They were designed to be played on them, after all.
I'm not saying these HDMI mods are useless, since obviously not everybody has space for a CRT, and I'm sure others aren't as sensitive to the inherent lag as I am. They're just relatively useless to me.

Regarding the NESRGB, mine was shipped yesterday and I can't wait to get it. I had been closely following the UniversalPPU project for quite a while when I heard about this on assemblergames. I have experience with some of Tim's work (GGTV) and am very happy with how well it works, so I have no doubt this thing will be excellent.

(NES wasn't technically made to be played with a new RGB board as it only used Composite & RF in the home and all, but whatever. ).

You can do that with RGB. Not with a HDMI NES or HDMI-modded N64 (The HDMI part at least).

Right. I meant stop worrying about HDMI. At least in this thread.

Okay, more for me then.

[leonk]

I'm always surprised by comments like "don't have space for CRT". Really!?? Were there a lot of families with no TVs in the 80's and 90's due to their inability to have space for a 19" TV?

I don't think so. I think TVs have simply became as much about asthetics as function. For many it's also about the spousal acceptance factor (trust me, it took me years to warm my wife to the idea of having 1 arcade machine in the family room!)

The nes HDMI is being targeted to more savvy retro gamers, I think that's a mistake. Hardcore retro gamers are going to only play on CRT. Kids born after 2000 that want to get into retro gaming are the target of HDMI. They don't care about crt because they didn't grow with it. They care about ease of use.

[adimifus]

(NES wasn't technically made to be played with a new RGB board as it only used Composite & RF in the home and all, but whatever. ).

That doesn't have anything to do with what I was talking about. I'll still be running it on a CRT. I was only saying I don't like playing older game systems on HDTVs. Hence I have no use for HDMI as most CRTs don't have HDMI inputs. (Were there any CRT HDTVs that had HDMI inputs? Those would probably be OK as far as lag is concerned...)

I'm always surprised by comments like "don't have space for CRT". Really!?? Were there a lot of families with no TVs in the 80's and 90's due to their inability to have space for a 19" TV?

I don't think so. I think TVs have simply became as much about asthetics as function. For many it's also about the spousal acceptance factor (trust me, it took me years to warm my wife to the idea of having 1 arcade machine in the family room!)

The nes HDMI is being targeted to more savvy retro gamers, I think that's a mistake. Hardcore retro gamers are going to only play on CRT. Kids born after 2000 that want to get into retro gaming are the target of HDMI. They don't care about crt because they didn't grow with it. They care about ease of use.

Probably more than the space issue, I think a lot of people just don't want to have two separate TVs for different things. Since Plasmas and LCDs were marketed as being slim and space saving, I could imagine some people being hesitant to going back to bigger CRTs, or having one in addition to a flat panel TV.
I agree 100% on the hardcore gamers thing. No matter what, the games will always look better on a CRT. If you really want a genuine experience, there's really no other option. In my mind, at least.

[ZellSF]

I personally have no interest in HDMI mods for any "classic" console (I'll say N64 generation and older). I am very sensitive to input lag, and any LCD/Plasma screen has enough lag to make it unenjoyable to play games on them, even with emulators already scaled to 1080p.

Complains about input lag on HDTVs... while playing on emulators. Sure you're not blaming the wrong thing here?

Even with real hardware, most options for connecting it to a HDTV results in input lag, a HDMI NES would fix that.

The nes HDMI is being targeted to more savvy retro gamers, I think that's a mistake. Hardcore retro gamers are going to only play on CRT. Kids born after 2000 that want to get into retro gaming are the target of HDMI. They don't care about crt because they didn't grow with it. They care about ease of use.

That's a lot of assumptions.

[Ed Oscuro]

Agreed on those points, although in its current implementation a HDMI NES will not completely eliminate lag, due to the buffering solution. How much this could be remains to be seen - I don't expect it to be high at all.

I think developing a completely digital pathway for old consoles is fated to happen as old CRTs die off. The apparent introduction of some possible lag source (via a buffer) is a shame, but unless you can license and implement G-SYNC, we're not yet at the point where this kind of tradeoff can be avoided. And again I would rather wait to see some tests on how much lag is caused in relation to a traditional CRT hookup - it might be so low that people have difficulty measuring it.

[adimifus]

Complains about input lag on HDTVs... while playing on emulators. Sure you're not blaming the wrong thing here?

Emulators do no inherently produce any noticeable lag, at least in my experience. I used to have my PC hooked up to my HDTV for gaming, and there was significant lag vs using a regular computer monitor.

I can understand why some people would want an HDMI output for their game systems, and that's fine. Its just not for me.

[ZellSF]

Complains about input lag on HDTVs... while playing on emulators. Sure you're not blaming the wrong thing here?

Emulators do no inherently produce any noticeable lag, at least in my experience.

They do. You're not as sensitive to input lag as you think, you just have a really laggy HDTV.

Hell even if emulators by themselves didn't cause input lag, there's tons of other computer factors that do.

[adimifus]

True, its possible every TV I've played on has significant lag. But regardless, I am very sensitive to it. I uto play guitar hero and rock band a lot (on Xbox 360), and the switch from CRT to any HDTV was almost impossible for me to adjust to. Even adjusting the delays in the game, it would take me hours to get it so it was comparable to a CRT. Again, I'm not saying there is no place for this, just that for me its not useful. In my experience, it is more than worth having a CRT set up next to my HDTV for older games/systems designed with that technology in mind.

And I have played emulators on PC hooked to to a CRT and not noticed much lag. At least not compared to any HDTV I've come across. In any case, nothing is as good as playing real hardware on a CRT, in my opinion.

[markfrizb]

A good example of lag would be a store like Walmart, best buy, or similar where they have a wall of different TV's all with the same input --- notice how some are slower to display the picture than others.

[ZellSF]

True, its possible every TV I've played on has significant lag. But regardless, I am very sensitive to it. I uto play guitar hero and rock band a lot (on Xbox 360), and the switch from CRT to any HDTV was almost impossible for me to adjust to. Even adjusting the delays in the game, it would take me hours to get it so it was comparable to a CRT. Again, I'm not saying there is no place for this, just that for me its not useful. In my experience, it is more than worth having a CRT set up next to my HDTV for older games/systems designed with that technology in mind.

And I have played emulators on PC hooked to to a CRT and not noticed much lag. At least not compared to any HDTV I've come across. In any case, nothing is as good as playing real hardware on a CRT, in my opinion.

(good) Emulators = not much input lag
(good) HDTVs = not much input lag

But here's the thing: it adds up. So playing emulators on a HDTV would be laggy, but it's not the fault of the HDTV by itself. If you had no emulator lag, maybe the lag would be low enough for you not to notice it at all.

True, its possible every TV I've played on has significant lag

Pretty likely actually, unless you're specifically hunting for low lag TVs (or monitors), you're very likely to end up with a laggy one.

[Ed Oscuro]

I don't think that emulators - I keep wishing somebody would actually do an empirical test of this; I would if I had the right equipment - add noticeable lag even in a PC environment.

On the other hand, it's pretty well established that many HDTVs add a considerable amount of lag even when used with HD sources. Add in a 240p signal and now you're getting bonus lag in the form of upscaling. Big lag + not really noticeable lag = Still big lag, and the major component of that is the major lag source - the TV most likely. Unless somebody can demonstrate otherwise, I think the situation is more like 1-3 frames lag from HDTVs (and upscaling, when needed) + a fraction of a frame from a PC emulator.

adimifus probably is right, in other words, about emulators not adding significant lag - at least if your frame of reference is HDTV lag. They aren't close to perfect in this perspective - perhaps there are plenty of games which really are harmed by lag on good emulators.

[ZellSF]

Here is the only reference I can find on short notice. byuu seems to suggest that SNES emulators need a minimum of 16ms for video buffering (1 frame, equal to the best of HDTVs) and often up to 60ms when you add in other PC factors (equal to really mediocre HDTVs). I think I read a test somewhere on the bsnes forums where the actual real life difference was measured and it was actually close to 3 frames.

Real hardware + XRGB-mini versus any SNES emulators I try and real hardware always wins out here, despite the XRGB-mini adding about 1.5 frames, suggesting the difference is greater than those 1.5 frames. With my monitor (which I think has 5ms input lag, no one would argue that's a noticeable amount) emulation is still much more laggy than my real SNES on a CRT. Of course that's all subjective testing... still I'm pretty confident it's correct.

[adimifus]

By no means do I claim to be an authority on any of this, I'm just sharing my experiences. I'm sure there are plenty of people that don't share mine.

[Ed Oscuro]

@ ZellSF: In that case, your rejoinder must be pretty accurate then.

I suppose part of the problem might be that on the PC front you actually can do an A / B test on something like VSync for a FPS - and notice the problem appearing and disappearing immediately. There's no way to test an emulator with or without lag, of course.

Hopefully faster PCs (of the future) will help push down some of the buffering issues, and G-SYNC should help eliminate one of the sources of lag too. Unfortunately you're still running on top of an OS which is inherently based around a lot of buffered systems and if you use stuff like desktop compositing (why can't I help but write "composting" here?), as byuu mentioned, it gets worse.

So quite possibly emulation doesn't feel bad because there's nothing to test it against, whereas moving from a CRT to a HDMI set and introducing scaling allows that A / B comparison.

[KKEYSER4063]

I despise input lag, and try to avoid as much as possible in my setup. However, LCD screens are a necessary evil for me - I honestly don't have the space to have two separate displays hookep up, nor do I want the hassle of having to switch cables, etc. between the two when I change input sources. I invested in a good, low-latency HDTV (Sony KDL-55W802A, which was clocked at about 17ms input latency, or 1 frame of lag), and I run a Micomsoft line-doubler into a scaler to output native 1080p. Is my setup as lag-free as a traditional CRT? Of course not. However, I have gotten the lag down to where I really don't notice it.

Also, my setup is versatile in that I can switch between legacy and modern sources instantly, and I have a measure of future-proofing built-in - should I need a new display or somesuch years down the road, I needn't worry about the availability of CRTs. They are easy enough to come by now, but to my knowledge few (if any) manufacturers still produce them, and eventually they WILL break down.

[adimifus]

I despise input lag, and try to avoid as much as possible in my setup. However, LCD screens are a necessary evil for me - I honestly don't have the space to have two separate displays hookep up, nor do I want the hassle of having to switch cables, etc. between the two when I change input sources. I invested in a good, low-latency HDTV (Sony KDL-55W802A, which was clocked at about 17ms input latency, or 1 frame of lag), and I run a Micomsoft line-doubler into a scaler to output native 1080p. Is my setup as lag-free as a traditional CRT? Of course not. However, I have gotten the lag down to where I really don't notice it.

Also, my setup is versatile in that I can switch between legacy and modern sources instantly, and I have a measure of future-proofing built-in - should I need a new display or somesuch years down the road, I needn't worry about the availability of CRTs. They are easy enough to come by now, but to my knowledge few (if any) manufacturers still produce them, and eventually they WILL break down.

Regarding the future and available displays, the HDMI out path is definitely a good thing. And, as with you, not everyone wants or has room for a CRT in addition to an LCD for that kind of stuff. Given the option though, at least until that option becomes unfeasable or unavailable, I'll choose and enjoy CRTs while they last.

[mufunyo]

Agreed on those points, although in its current implementation a HDMI NES will not completely eliminate lag, due to the buffering solution. How much this could be remains to be seen - I don't expect it to be high at all.

With a system-wide custom implementation like emulating the whole system on an FPGA, the emulated PPU could directly write into the front buffer. As long as emulation is cycle-accurate and all the timing checks out, you can have the hardware scanout pointer (which streams the data line by line over the HDMI port) trail behind, and have a theoretical minimum lag of 1 scanline (63 µs). Any scan doubling would need to be directly implemented in the routines that write pixels to the front buffer, and only integer multiples of 240p would be possible.

Alternatively, you could implement the HDMI protocol directly into the FPGA, and have a virtual "HDMI PPU" of sorts. That would also be virtually lag-free.

[Ed Oscuro]

Well, to nitpick, we've already gone over the point of the system not being emulation. I just want to bang on that drum again...it doesn't mean that the CPU reimplementations are going to be cycle-accurate, but when you can reimplement the CPUs it's likely some points of divergence in emulation from the originals have been removed.

Using the 240p resolution as your output seems to destroy one of the big intended benefits of a native HDMI implementation - eliminating external scalers. It wouldn't be a big problem if you could scale (as you mention) to a larger resolution close to something the target display will like, but I'm not sure of that and the results might be less than endearing.

I talked about implementing the HDMI protocol on the FGPA before as well.

Thanks for your description of writing to the front buffer and the minimum lag - I take it you come to the 1 scanline minimum figure after intra-scanline effects have been established, right? I found the description very useful. I do wonder about the description of the front buffer, though - instead of a nearest-neighbor upscaling method used on an entire frame, I don't see why it wouldn't be possible to map and multiply "original" scanline output to a specific number of scanlines to be present in the HDMI output, varying the number of HDMI scanlines according to the position of the scanline. The mapping would be determined by deciding beforehand how many times to repeat a scanline so that it reaches the target output (i.e. 1080p). Sync pulses can be used to find the position of the original scanlines on the screen, right?

[mufunyo]

Using the 240p resolution as your output seems to destroy one of the big intended benefits of a native HDMI implementation - eliminating external scalers.

I did mention scaling, but only integer multiples of the original resolution. So, 480p, 720p, 960p, 1200p.

Thanks for your description of writing to the front buffer and the minimum lag - I take it you come to the 1 scanline minimum figure after intra-scanline effects have been established, right?

I mean 1 scanline (at 240p) more lag than the original hardware. If the original NES delays pixel output to accommodate special effects, then any lag you get from the HDMI scanout only adds more on top of that existing lag.

Instead of a nearest-neighbor upscaling method used on an entire frame, I don't see why it wouldn't be possible to map and multiply "original" scanline output to a specific number of scanlines to be present in the HDMI output, varying the number of HDMI scanlines according to the position of the scanline. The mapping would be determined by deciding beforehand how many times to repeat a scanline so that it reaches the target output (i.e. 1080p).

This is what I mean by integer multiples -- you can write the same colour value to multiple locations in the front buffer, effectively duplicating pixels without adding an extra scaling step. However, uneven duplication like what would be necessary for 1080p would look bad, so you want to stick to integer multiples. For a 1080p output, you could output 960p, and output black pixels during part of the vertical front/back porches to create black bars. The picture wouldn't fill the entire screen, but you would have even scaling. Depending on the original NES timing, you may have to delay hardware scanout further to give you the wiggle room needed to output the black bars, though. Off the top of my head, I think you have about 4ms of vblank in between NES frames?

[Ed Oscuro]

I mean 1 scanline (at 240p) more lag than the original hardware.

Oh, worst-case, right? Because at the time the full scanline has been written, it's available to be sent through the HDMI signal, right?

1080p duplication might look bad but it is already standard for MAME. I think it's not that big a deal to gain a large picture without resorting to buffering, although having a letterboxed mode (as you describe) would be important too. 4ms of vblank in the NES may well be the case due to the significant overscan amount used in those systems.

[evil_ash_xero]

Maybe we should have another thread split, just for this HDMI NES. It seems to be a popular topic.

[ZellSF]

Maybe we should have another thread split, just for this HDMI NES. It seems to be a popular topic.

It already has its own topic. We're just not very good at staying in it (it's at page 4 or so).

[adimifus]

I can't remember if this has been mentioned before (I think it was, but I can't find it), but with the provided connector, is there an existing cable that will work with this, or will it require a custom made cable?

[mufunyo]

I can't remember if this has been mentioned before (I think it was, but I can't find it), but with the provided connector, is there an existing cable that will work with this, or will it require a custom made cable?

You can get a pre-made cable from viletim's website.

[antron]

Does any other NES video improvement project utilize the original PPU for graphics (sprites, etc.) and their timings?

To me that seems to be the key feature of this solution.

[Greerdom]

Cannot wait to grab one of the boards and SCART cable. Anyone know of a good modder in North America/US?