VOGONS


First post, by Mau1wurf1977

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Hmm not much going on in this emulation thread, but I lately stumbled over this issue and I'm sure someone knows something that could help.

I'm mostly talking about NTSC games which run at 60Hz. But apparently it's not exactly 60Hz and often a fraction off (so slightly different to your 60Hz on your Windows machine).

So let's say the console i set to 59.98 Hz and your screen runs at 60.02 Hz. Now some (good) emulators allow you to simply emulate a console that runs at 60.02 Hz. So in effect changing the speed a little bit.

MAME has this option: Sync to Monitor refresh.

This works beautifully. The scrolling is smooth and there aren't any jerks at all.

But I'm having issues finding emulators for other systems (like Genesis or SNES) that do the same thing. They often have an option Vsync, but it doesn't change the emulators underlying frequency and while you do get smooth scrolling, you will get a "jump" every once in a while...

So I'm wondering if anyone else has noticed this and found solutions?

EDIT:

What about when you use a CRT monitor. Would that fix the issue?

Reply 1 of 6, by Jorpho

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http://forums.emulator-zone.com/archive/index … hp/t-16272.html suggests the problem can ultimately be traced back to difficulties in setting the refresh rate on certain graphics card chipsets.

However, what exactly leads you to conclude that this "jump" is due to some infinitesimal mismatch in the refresh rate and not some other system issue? I would suggest using a DOS or Linux boot disk and verifying that the same problem occurs outside of Windows.

Reply 2 of 6, by keropi

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I just checked FUSSION (a sega 8/16/32x emu) and it works perfectly fine with VSYNC on and fullscreen at 60hz....
Just load Alex Kidd in Miracle world and leave the demo to the motorcycle scene... the scrolling is perfect

for PAL games I tend to make a screenmode with 100hz refresh rate and make the emu run at this resolution...

You must remember that not all console games have perfect scrolling - even in real systems... take for example Super Mario 2 Yoshi's Island for the SNES... it renders 60fps but it really is less ...

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Reply 3 of 6, by Mau1wurf1977

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keropi wrote:

I just checked FUSSION (a sega 8/16/32x emu) and it works perfectly fine with VSYNC on and fullscreen at 60hz....
Just load Alex Kidd in Miracle world and leave the demo to the motorcycle scene... the scrolling is perfect

for PAL games I tend to make a screenmode with 100hz refresh rate and make the emu run at this resolution...

Fusion 364 is what I'm using for Sega and BSNES for SNES. I have tested on two machines (desktop with Nvidia and netbook with Intel graphics).

Are you using a CRT screen? That might make a difference. Does your screen habe an on-screen menu that displays the refresh rate? Could you check on the desktop and inside the emulator (full-screen) and see if there is a difference?

Jorpho wrote:

However, what exactly leads you to conclude that this "jump" is due to some infinitesimal mismatch in the refresh rate and not some other system issue? I would suggest using a DOS or Linux boot disk and verifying that the same problem occurs outside of Windows.

It's documented in various readme / help files of various emulators. While you can change the internal speed of the emulator, this will then cause issues with the audio. So it's really quite tricky.

Haven't tried DOS / Linux yet because I usually struggle to get things going (Installation). Will give it a go though. Because the LCD does take slightly off frequencies such as 59 and 61 Hz.

Reply 4 of 6, by Barry_Purplelips

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Use PowerStrip for precise timings. Normally a decent emulator will offer some sort of compensation (which may not necessarily alter the internal clock) when syncing to non-standard refresh rates, but in most cases this is limited to decimals and not something extreme like going from 59.94 to 75.

What you really want to do is get you timing as close as possible to that of the console and go from there, and yes, a CRT will help big time. LCD's and Plasmas are garbage, specially for this task.

Reply 5 of 6, by keropi

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nope I am using an LCD screen, a 24" 1920X1200 one to be precise ... refresh rate is 60hz

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