Demon Attack runs very strange

[eightbit]

The Vic-20 core for the most part is very nice, but there is some weirdness going on with some game titles. I know I have seen this in other games, although I can only recall one at the moment.

If you play Imagic's "Demon Attack" its almost like it is pausing and unpausing rapidly. It does not play this way on real hardware. On a real Vic-20 (I have one here with the game) it is fast and smooth playing...just as any other version.

I first thought it was a PAL/NTSC issue but it is not. Then I thought it might have been the ROM dump, so I tried all of them from the TOSEC set. The same rom running on a real Vic works fine.

[beamrider]

Yes, I notice that I couldn't play Frogger07, the screen rolls like a CRT with a mal-adjusted vertical hold.

[kathleen]

@beamrider,
I've just tried Frogger'07 under the last Vic20 core and the issue happens also if the screen center option is not = NONE (see below).
Have you checked this ?
There is still a vertical bar at the left side of the screen (whcih can be addressed by an horizontal adjustment of the monitor) but the image does not scroll at all and the game is fully playable

[kathleen]

I first thought it was a PAL/NTSC issue but it is not. Then I thought it might have been the ROM dump, so I tried all of them from the TOSEC set. The same rom running on a real Vic works fine.

Well this is also weird, have tested it on my Mister and it works w/o any issue. I do not have this pause/run problem