50Hz sync in WinUAE

[amiga]

Originally Posted by Supamax

...
- the XBOX "OS" is fast and light (compared to Windows),
...

the XBox "OS" IS a stripped-down version of Windows made specifically for the XBox.

[koseidon72]

Originally Posted by gary

For some reason I had to use a hacked version of WinVice and run it at 99% speed to get smooth scrolling but WinUAE seemed fine. This is probably the easiest way to get smooth scrolling but you may want to have a dedicated PC sitting near the TV set for emulation instead of using your main PC.

Hi, could you please tell me where I could get this hacked Winvice version?
Thanks

[Hobbe]

I use the combination below plus NTSC chipsets for most of the PAL-exclusive games I play. Nevermind the lil speedup, this way I get to see the whole 320x256 picture filling the screen without any sort of stretching, moving at 60 frames per second (yes, PAL users don't know what REAL smooth scrolling is )

[Toni Wilen]

Originally Posted by Retro-Nerd

@Toni

Can you give me the technical answer why the refreshrate doubling causes the motion blur (scrolling games, CRT) in 100Hz for PAL games and 120Hz for NTSC games?

No idea (and I don't have any CRT displays anymore)

[Retro-Nerd]

Oops, this surprises me. I thought this was a known problem. Noticed this already in 2001, when i tried some PAL games in 100Hz. PAL 50Hz works of course, but this flickers as hell. NTSC 60 2D games, i.e. Genesis/SNES, works without any blurring in 60Hz, but suffers from the same issue in 120Hz.

[alexh]

I've never tried 100Hz (as 50Hz works fine here)

With vsync on, output rate of 100Hz then each frame is going to be on screen for the same amount of time (two * 100Hz frames). So the blur cannot come from the rendering itself.

If there is any blurring it would have to be a feature of your CRT / Video card DAC at 120Hz?

Try a lower video card screen resolution?

If you have a very low persistence phosphor I guess redrawing the screen twice could result in a brightness difference? But I dunno why it would only affect objects in motion?

[Retro-Nerd]

Well, i had several graphic cards and monitors in the last 8-9 years. I noticed this each time. Some say it's the pixel afterglow. But this sounds not like an technical answer, more like a symptom.

Edit: Just got an explanation. Imagine a scrolling, which only moves every second frame. You can't trick the human eye. It's comparable with the fast camera pannings in movies.

Sound like a good explanation for me.

[chiark]

Originally Posted by Retro-Nerd

You can't trick the human eye.

Never. No.



the human eye isn't synchronised to a 100Hz picture: it cares not whether it's looking at a 50Hz image or a 100Hz image refreshed twice...

[Photon]

Originally Posted by chiark

Never. No.



the human eye isn't synchronised to a 100Hz picture: it cares not whether it's looking at a 50Hz image or a 100Hz image refreshed twice...

Excuse me, that's bullshit. I have a 50Hz-capable CRT which can also do 100 and 150 Hz. It's easy to see that 50Hz synced is best. Just run a game with scrolling, or a demo with lots of moving objects (both full framerate) and you'll see the ghosting.

[Calgor]

You can tell the difference from 50Hz to 100Hz unless you have very unsensitive eyes to the flickering. Regarding any extra motion blur on higher refresh rates due to the CRT phospor going down in brightness slowly, I never did notice the difference, maybe that is harder to notice - the theory does make sense to me as I can see it is a bit slow at 50Hz, and if brightness goes down at same pace, it will be there longer due to the repeated frame in 100Hz. But like I said, I never noticed that. Could be most games were 25fps.

[gary]

Originally Posted by koseidon72

Hi, could you please tell me where I could get this hacked Winvice version?
Thanks

Heres the thread I found at Lemon64. The executable I'm using is "x64e.exe" as opposed to "x64.exe" the official exe.

http://www.lemon64.com/forum/viewtopic.php?t=22546

[alexh]

Originally Posted by Retro-Nerd

Imagine a scrolling, which only moves every second frame. You can't trick the human eye. It's comparable with the fast camera pannings in movies.

It only moves every second frame, but the frames stay on the screen for only half the time.

If there is no visual difference on the screen (i.e. brightness) between frames then there is no difference between a 100Hz display updated every second frame and a 50Hz screen!

I cannot see any comparison with fast camera panning..??

Originally Posted by Photon

Excuse me, that's bullshit. I have a 50Hz-capable CRT which can also do 100 and 150 Hz. It's easy to see that 50Hz synced is best. Just run a game with scrolling, or a demo with lots of moving objects (both full framerate) and you'll see the ghosting.

Empirically I would agree, I just do not know why.

[Retro-Nerd]

Originally Posted by alexh

It only moves every second frame, but the frames stay on the screen for only half the time.

If there is no visual difference on the screen (i.e. brightness) between frames then there is no difference between a 100Hz display updated every second frame and a 50Hz screen!

I cannot see any comparison with fast camera panning..??


Empirically I would agree, I just do not know why.

Have you ever played games like Ruff'n Tumble or Wolfchild on a 50Hz TV? These games scrolls in 25 FPS. You will never see a crystal clear background when the game starts to scroll. This is what i and others meant with the ghosted or blurred image.

You can transport these effect to PC emulation with a Hz doubling. The Turrican 50 FPS scrolling background looks always sharp on a 50Hz TV, but try it in WinUAE with a 100Hz PC CRT. It suffers from the same effect. Ruff'n Tumble and all other 25 FPS scroller looks ever worser.

[Toni Wilen]

Real Amiga display is still ALWAYS updated at 50Hz (only exceptions are programmed modes)

[Retro-Nerd]

Sure, but what happens in the mentioned games on a real Amiga? The background isn't sharp during the scrolling, permantently.

[gary]

Originally Posted by Retro-Nerd

Have you ever played games like Ruff'n Tumble or Wolfchild on a 50Hz TV? These games scrolls in 25 FPS. You will never see a crystal clear background when the game starts to scroll. This is what i and others meant with the ghosted or blurred image.

You can transport these effect to PC emulation with a Hz doubling. The Turrican 50 FPS scrolling background looks always sharp on a 50Hz TV, but try it in WinUAE with a 100Hz PC CRT. It suffers from the same effect. Ruff'n Tumble and all other 25 FPS scroller looks ever worser.

I think smooth scrolling non-interlaced games like Turrican update the screen 25 frames each second, even though the graphics chip may output the signal at 50hz (50 frames per second). Many demos refer to 25fps as 'full frame' I think. You're right that Ruff'n'Tumble on a real Amiga doesn't scroll smoothly but I'm not sure what the real frame rate for that game is (12 fps maybe?). I remember reading an interview with one of the Super Cars 2 programmers explaining that the game averages an update rate of about 8 frames per second.

[Adropac2]

Lcd monitors don't exactly help either and the most i ever got from mine was a very smooth blur - being that it was Lcd of course

Has Lcd response time improved any over the years regarding this or is crt still the best bet for 100% non blurring of fast scrolling movement?

[Toni Wilen]

Originally Posted by gary

I think smooth scrolling non-interlaced games like Turrican update the screen 25 frames each second

No, no and no. It is 50Hz.

[gary]

Originally Posted by Toni Wilen

No, no and no. It is 50Hz.

Definitely 50hz video output, but I thought in terms of screen updates as far as the software is concerned it is 30 updates per second for NTSC and 25 for PAL. I'm probably getting the descriptions wrong:

THE OFFICIAL comp.sys.amiga.introduction FAQ
(last updated on May 3, 1998)

** What's this PAL and NTSC stuff all about?

Video signals for television in North America are different from those
used in Europe. North America uses the NTSC system, and most European
countries, as well as many others, use the PAL system. Since the Amiga
uses video-based screen modes, they are made for the different modes
according to the country.

The main differences between the two modes are resolution and frame
rate. NTSC displays have 200 lines vertically, or 400 in interlaced
mode, and displays 29.97 frames (59.94 fields) per second (most people
round it off to 30). PAL uses 256, or 512 interlaced, with a frame
rate of 25 frames per second (50 fields).

I also remember messing about with animation playback and found 25 frames per second to be smooth on a PAL Amiga.

[Toni Wilen]

Originally Posted by gary

Definitely 50hz, but I thought in terms of screen updates as far as the software is concerned it is 30 updates per second for NTSC and 25 for PAL. I'm probably getting the descriptions wrong:

Yes and no

PAL is 25 frames per second = 50 fields per second (one interlaced frame is 2 fields)

Amiga (and basically all 8-bit and 16-bit home computers) used "progressive" PAL mode where odd and even frames start at same position. (this is also the reason for "scanline" effect)

Regular PAL TV signal was always interlaced and 25fps.

Modern LCD displays seem to handle this incorrectly, result is ugly 25fps screen updates..

I also remember messing about with animation playback and found 25 frames per second to be smooth on a PAL Amiga.

25Hz isn't smooth. (perhaps it was interlaced?)