Celtic "Meeting Demo", Timing problems in Cycle Exact Mode

StingRay · 26 January 2018, 08:15

I've just watched Celtic's Meeting Demo in the latest WinUAE (3.6) and noticed that the demo runs very slow in cycle exact mode. I didn't check the demo code yet so it might either be a demo bug or a problem with UAE. Might be worth to check.

Problem is easy to reproduce, just set standard A500 quickstart config and run the demo, the logo movement in the upper part will be very slow.

Foebane · 26 January 2018, 11:44

It IS slow in C-E mode, and what's more, there is a lot of stippling pixels in the bottom scroller part, when the screenshot from Pouet.net indicates none (https://www.pouet.net/prod.php?which=21211). Maybe a corrupted file?

ross · 26 January 2018, 12:04

Try with no fast mem

Toni Wilen · 26 January 2018, 14:38

This. Real A500 confirmed, 0.5M+0.5M results in identical behavior. Chip RAM only fixes it.

StingRay · 26 January 2018, 14:50

Case closed then.

StingRay · 26 January 2018, 15:15

OK, so I had a quick look at the code now, problem is apparently caused by the VBI code. If interrupt code is disabled, the problem is gone.

26 January 2018, 08:15	#1
StingRay move.l #$c0ff33,throat Join Date: Dec 2005 Location: Berlin/Joymoney Posts: 6,865	Celtic "Meeting Demo", Timing problems in Cycle Exact Mode I've just watched Celtic's Meeting Demo in the latest WinUAE (3.6) and noticed that the demo runs very slow in cycle exact mode. I didn't check the demo code yet so it might either be a demo bug or a problem with UAE. Might be worth to check. Problem is easy to reproduce, just set standard A500 quickstart config and run the demo, the logo movement in the upper part will be very slow.

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26 January 2018, 11:44	#2
Foebane Banned Join Date: Sep 2011 Location: Cardiff, UK Age: 51 Posts: 2,871	It IS slow in C-E mode, and what's more, there is a lot of stippling pixels in the bottom scroller part, when the screenshot from Pouet.net indicates none (https://www.pouet.net/prod.php?which=21211). Maybe a corrupted file?

26 January 2018, 12:04	#3
ross Defendit numerus Join Date: Mar 2017 Location: Crossing the Rubicon Age: 54 Posts: 4,498	Try with no fast mem

26 January 2018, 14:38	#4
Toni Wilen WinUAE developer Join Date: Aug 2001 Location: Hämeenlinna/Finland Age: 49 Posts: 26,574	This. Real A500 confirmed, 0.5M+0.5M results in identical behavior. Chip RAM only fixes it.

26 January 2018, 14:50	#5
StingRay move.l #$c0ff33,throat Join Date: Dec 2005 Location: Berlin/Joymoney Posts: 6,865	Case closed then.

26 January 2018, 15:15	#6
StingRay move.l #$c0ff33,throat Join Date: Dec 2005 Location: Berlin/Joymoney Posts: 6,865	OK, so I had a quick look at the code now, problem is apparently caused by the VBI code. If interrupt code is disabled, the problem is gone.

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