Hello, howdy, and how do I pull of 50Hz@emu & 60Hz@host ?

[Einstein]

Goal:
To have WinUAE to "blit" the display buffer (current buffer) of the emulated Amiga every 1/60 of a second (60Hz) while the emulated Amiga keeps its own pace (PAL) of swapping the buffers every 1/50 of a second (50Hz).

Obviously I want to pull it off to have smooth scrolling in PAL mode (regardless of the little display artefact we are familiar with). I can raise the FPS to 60Hz offcourse but then the emulated Amiga follows up to 60Hz as well, which obviously isnt 50Hz anymore  :crazy:  and causes an annoying laggy scroll experience, so how do I do it ?

Thanks !

[arkpandora]

Hi,

I have no recent enough computer to emulate an Amiga in decent conditions, therefore I haven't investigated any Amiga emulator on that point.

However this is my concern as well, and to my knowledge you can't do that : the only solution would consist in creating a 50 Hz screenmode with some tool like Powerstrip and manage to have your computer output 50 Hz without any signal conversion between the emulator and the VGA output.  According to some advices I had in the past here on that subject (which I haven't applied yet), using a TV-out output and a tool such as TVTool may help.

Edit : Another option is to display the emulator on a 100 Hz screen while activating the emulation speed adjusting.  Then in theory you should get normal animation and almost normal speed.

[Einstein]

I will investigate that Powerstrip, and meanwhile a little correction; I wrote that changing the FPS from 50Hz to 60Hz causes annoying lags, not true, in fact it creates smooth scrolling, but in 60Hz. This FPS raise however also causes the emulated Amiga (I wrote correctly this time) to raise its display buffer swapping from 50Hz to 60Hz, which although smooth scrolls, it does it too fast obviously.  :pissed:

[Einstein]

Since my Plug-n-Play (^_^) monitor doesnt _seem_ to support refresh rates below 60Hz and above 85Hz and I dont have the guts to force the desired rates with Powerstrip I'm not going to get my 50Hz (or 100Hz) smooth scrolling experience am I ?
Dammit this is annoying, all (Win)UAE needs to do is to flush the emulated amiga's current display buffer at 60Hz while having the emulated vertical frequency set at 50Hz, and I would be a happy Virtual PAL Smooth Scroller fellow!

[arkpandora]

Some LCD monitors can display frequencies below those they advertise, but for such tests it would be easier to use a CRT monitor which is able to display both 50 and 100 Hz.

Dammit this is annoying

How I understand !  The fact that I still haven't seen a modern computer display 50 Hz animations accurately is the main reason why I'm so determined to try to make my defective Amigae (I am suddenly thinking of this pleasant Latin-form plural) work again.  But if it works in 60 Hz, it should work in 50 Hz.

all (Win)UAE needs to do is to flush the emulated amiga's current display buffer at 60Hz while having the emulated vertical frequency set at 50Hz

In order to do this, to my knowledge the emulator should have to create frames which are not in the original animation.  Every new frame should be an intermediate drawing between the previous frame and the next frame.  In order these frames to go unnoticed, the emulator should use a combination of anti-aliasing and pixel scaling methods, which would depend on the emulator's screen mode and the computer's power.  It might be a complex thing to program - but I'm not a coder - and would require even more processing power.

[Einstein]

arkpandora wrote:

all (Win)UAE needs to do is to flush the emulated amiga's current display buffer at 60Hz while having the emulated vertical frequency set at 50Hz

In order to do this, to my knowledge the emulator should have to create frames which are not in the original animation.  Every new frame should be an intermediate drawing between the previous frame and the next frame.  In order these frames to go unnoticed, the emulator should use a combination of anti-aliasing and pixel scaling methods, which would depend on the emulator's screen mode and the computer's power.  It might be a complex thing to program - but I'm not a coder - and would require even more processing power.

Well, forget about it needing to be unnoticed, I take anything smooth scrolling at 50Hz that I may experience.
I probably should have simply written that what WinUAE needs to do (as an option) is to forget about vertical syncing the host computer display to that of the emulated Amiga display, that is, it _really_ (I'm desperate) should (as an option), simply as I wrote, to flush the emulated amiga display (that the copper bitplane pointers point to) once every 60th of a second, this while updating the copper register(s) that hold(s) the current vertical beam postion (yea I dont remember the names and such) at a rate that it vertically resets once every 50th of a second.

MAME does this beautifully, I dont see why (Win)UAE wouldnt be able to perform this simple task !

*edit*

Offcourse MAME knows no copper!  ;-)

[arkpandora]

Well, forget about it needing to be unnoticed, I take anything smooth scrolling at 50Hz that I may experience.

In order the animation to be smooth, the additional frames must go unnoticed.

But I was wrong : every original frame would have to be modified in order to simulate every 60th of a second what the eye would see at the same time on a 50 Hz screen.

As I don't know how the copper works (I'll have to learn one day), I don't follow you well, and I still can't imagine how you could maintain both perfect animation and emulation without drawing new frames or accelerating the display.  Is MAME really able to do that ?

[keropi]

75hz is your answer if u have a 50hz pal screen and your monitor cannot go above 85hz

[arkpandora]

Why 75 ?