Picodrive Vs Megadrive


Epicenter, look at Neo Geo - system much much more powerful than MD. NG had Zilog Z80A for general sound operation, FM chip: Yamaha YM2610 15 Sound Channels - 7 Digital, 4 FM synthesis, 3 PSG, and 1 Noise Channel. This IS a bit more powerful and tricky to emulate, isnt it? So why we haven't problems with NG sound in emulators? neoragex, kawaks, even gp2x ng emu sounds wery well ?? With beefier 12mhz M68K CPU to emulate, not to mention much more advanced video processor...
It's not an issue of speed, so I don't know why you're even mentioning the graphics hardware or CPU clockrate. The issue is accuracy to original hardware audio. At any rate, there is less noticable inaccuracy of emulation of the NeoGeo's audio to the MegaDrive's because most NeoGeo games produce the vast majority of their sound by playing a series of pre-recorded ADPCM data. If you strip that out, there is very little FM actually being produced by the YM2610-and-company. Most MD games use a bare minimum of PCM samples, if any at all, and rely on the YM2612 and PSG for all of their audio.

At any rate, adding more channels really doesn't make it harder to make the sound more accurate, just more stressful. Once the concept is down and the chip is understood, it's trivial to just emulate more channels. The problem is fundamental. It will never sound as good as the real thing will. It can come pretty close, like accurate NES and SMS/GG emulators do, but they're still not right on the money, and they still hog more CPU horsepower than the GP2X or any handheld emulation device has to offer.
 
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Epicenter, look at Neo Geo - system much much more powerful than MD. NG had Zilog Z80A for general sound operation, FM chip: Yamaha YM2610 15 Sound Channels - 7 Digital, 4 FM synthesis, 3 PSG, and 1 Noise Channel. This IS a bit more powerful and tricky to emulate, isnt it? So why we haven't problems with NG sound in emulators? neoragex, kawaks, even gp2x ng emu sounds wery well ?? With beefier 12mhz M68K CPU to emulate, not to mention much more advanced video processor...
It's not an issue of speed, so I don't know why you're even mentioning the graphics hardware or CPU clockrate. The issue is accuracy to original hardware audio. At any rate, there is less noticable inaccuracy of emulation of the NeoGeo's audio to the MegaDrive's because most NeoGeo games produce the vast majority of their sound by playing a series of pre-recorded ADPCM data. If you strip that out, there is very little FM actually being produced by the YM2610-and-company. Most MD games use a bare minimum of PCM samples, if any at all, and rely on the YM2612 and PSG for all of their audio.

At any rate, adding more channels really doesn't make it harder to make the sound more accurate, just more stressful. Once the concept is down and the chip is understood, it's trivial to just emulate more channels. The problem is fundamental. It will never sound as good as the real thing will. It can come pretty close, like accurate NES and SMS/GG emulators do, but they're still not right on the money, and they still hog more CPU horsepower than the GP2X or any handheld emulation device has to offer.

You're always talking about sound emulation, but what about graphics? Actually this whole topic is about graphics, and as you can see on the screen shots they are not as good as they could be compared to the original Megadrive, and they may be improved with some 'TV Effect' filter, as seen in other emulators
I do not code emulators, but I think much can be done with the remaining GP2X cpu speed, according most can go up to 266, or at least 240 :)


off-topic : Is there any 'tech demo' out there, showing the best Genesis can do?
I saw a 32X demo, rendering a 3D scene, comparable to PSX graphics with textures and shadings etc, but very limited range of view, but what about Genesis alone?
 
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You're always talking about sound emulation, but what about graphics? Actually this whole topic is about graphics, and as you can see on the screen shots they are not as good as they could be compared to the original Megadrive, and they may be improved with some 'TV Effect' filter, as seen in other emulators
I do not code emulators, but I think much can be done with the remaining GP2X cpu speed, according most can go up to 266, or at least 240 :)

The emu for the GP2X is made to run on the LCD at 1:1. The TV-out will scale it to display on the TV as an afterthought. You will get a bit of artifacting from this. The Genesis outputs from the system direct and is designed and tuned for TV output.. Then there is the fact that the GP2X TV out is sharper with S-video then the Genesis ever was with it's craposite or worse RF (RF stands for Really Fuzzy...well to me it does) output. You will see a more detailed image that exposes the cheating that they used to do to simulate more colors or transparencies. Basically on the Genesis they exploited the fact that adjacent pixels would smear together in composite and give the illusion of more colors and even transparencies. Look at Sonic, those "waterfalls" used alternating vertical lines looking like transparencies. On the sharp GP2X screen you see them as vertical lines and not transparent. I used to have my Genesis connected with an RGB cable that I hacked together. It basically looked like the GP2X does now.
 
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If you want to see the MD/Genesis do some impressive and usual things-- check out Red Zone. The whole game is like a ridiculously over-the-top tech demo, but quite fun as well. It even includes smooth video in the introduction, much smooter and with better use of color than that Matrix clip.. :) If you want to see what the MD is capable of in 3D, Kawasaki Superbikes is a good example, most of the rest of the 3D games were poorly coded so they run slowly. Panorama Cotton is an incredible game that uses sprites to produce 3D in a very creative fashion, at a very high framerate. Ecco 2 pushes the hardware in lots of unusual ways, especially tricks to get more colors on the screen at once, very unusual and unique enemy movement algorithms and more.

I didn't comment on graphics because:
#1, graphics in an emulator are supposed to look different from how the console displays on a TV because you are comparing an analog signal to a digital one
#2, the pictures in the original post didn't work when I came to the thread, it was a lycos error.

Basically on the Genesis they exploited the fact that adjacent pixels would smear together in composite and give the illusion of more colors and even transparencies. Look at Sonic, those "waterfalls" used alternating vertical lines looking like transparencies. On the sharp GP2X screen you see them as vertical lines and not transparent. I used to have my Genesis connected with an RGB cable that I hacked together. It basically looked like the GP2X does now.
This is why I never use RGB... it really spoils the illusion.
 
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But don't you see, the illusion takes away from the pin-point accuracy we all love so much ;)

- Alex
 
Would it be possible to have some sort of... erm.. composite emulation, so you can enable a filter so these tricks can take advantage of "problems" with composite video? It should obviously be toggled...
 
But don't you see, the illusion takes away from the pin-point accuracy we all love so much ;)

- Alex
RGB may be more accurate hardware-wise but you won't get the same experience. For example, I grew up with a TV running the games on RF or composite so it has nostalgic value for me, and playing with an emulator or RGB makes it feel too artificial.

Sure, you can 'emulate' composite, it just won't look quite right. There's some NES emulator that does a decent job of it, IIRC. The existing MegaDrive emulators don't offer a very good equivalent though, Kega Fusion's 'TV Mode' looks kind of similar but it's more just generically blurred, it doesn't take on the attributes of NTSC that were really advantageous, but it does provide some degree of simulation of more colors, at least.
 
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But don't you see, the illusion takes away from the pin-point accuracy we all love so much ;)

- Alex
RGB may be more accurate hardware-wise but you won't get the same experience. For example, I grew up with a TV running the games on RF or composite so it has nostalgic value for me, and playing with an emulator or RGB makes it feel too artificial.

Sure, you can 'emulate' composite, it just won't look quite right. There's some NES emulator that does a decent job of it, IIRC. The existing MegaDrive emulators don't offer a very good equivalent though, Kega Fusion's 'TV Mode' looks kind of similar but it's more just generically blurred, it doesn't take on the attributes of NTSC that were really advantageous, but it does provide some degree of simulation of more colors, at least.

The Bsnes emulator for windows has an NTSC filter that makes the whole screen on the pc monitor look like a TV. It's actually quite impressive and accurate looking to me, but it slows down the already cpu intensive emulator. I don't know of any Megadrive emulators that do this. The look is nice though. I don't know if something like this could be implemented in any of the MD emulators, especially for the GP2X. It might require to much processing power.
 
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Point is, to have the audio truly accurate, the CPU requirement for the GP2X will be at least 4 times greater. Probably much, much more. I don't really see that kind of effort being poured in in the future when most users won't demand such a level of accuracy. I can put up with it when playing a game because I have to make some sacrifices to make it portable, is how I view it. When I need the perfect MD experience I'll use my real MD. However in DrMDx at least, while speed was good, audio compatibility was terrible even with the highest accuracy setting. A lot of weird sounds that played off-key, at the wrong time, or just as static or garbage. DrMDx acts like a mid-90s MD emulator, which are some of the fastest, but some of the most inaccurate. It just takes a lot of dedication to change things like that, but it's also an issue of speed-- the GP2X's CPU is worked very, VERY hard and requires a huge overclock with DrMDx's highest accuracy. PicoDrive is a step in the right direction though.
 
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