Yea I noticed that even pressing buttons to change speed almost always results in an immediate stutter on the first few frames after the speed change, so there's very much a bug at least as far as I'm concerned.


Ah that explains it! I have been away for a few days during the holidays here in ...

Ill make sure to test it in PAL mode first also to see if the stutter occurs in both or just one.

Nice gaming setup by the way!

Thank you so much for testing! I must admit, the stutter isn´t really every 1-2 seconds, but more like every 4-5th maybe if I let it go at the same speed. Initially I jumped alot up and down with the speed and thats maybe why I experienced it more frequently (I was also quite frustrated since I ...

Yeah my screen is set to 60hz refresh rate.

Genesis NTSC 60hz (emulator), the test suite is silky smooth in both hori and vert tests
Duckstation 60hz emulator, vertical test stutters at the higher speeds, just like my psx :(

in this test

Skärmklipp.PNG

Really strange that your psx doesnt ...

I can also add, that I tried the 240p test suite in my genesis again, supersmooth scrolling.
Fired up the genesis emulator core in retroarch, loaded the test suite.. smooth scrolling in vertical test.
Loaded it again in psx emu Duckstation and it stutters in the vertical test.

I need to find a real game that has some infinite scrolling or something so that I can see if this really is a issue at all when playing real games hahaha damn I got totally stuck in my way of thinking after the DFO mod.. I really wanted to test that it was correct and thought the 240p test suite ...

When I got home I remembered that the test suite came in 2 versions.. one for real HW and one for EMULATORS.
First I thought it might be a silly test, but best to rule out all other posibilities.

I got the 240p emulator version upp and running in Duckstation, and I´ll be damned.. it behaves just as ...

Yeah I guess you are right.. the speed shouldnt cause this.. hmm
I tried to make a video of the shimmering but its very difficult to film the CRT screen to capture the shimmering effect with my phone.. so much else going on with the CRT that the phone captures. But I will try and see again after ...

Thanks for the input :). I have tried on 2 different CRTs, one Sony Trinitron, one B&O. Even used 2 different brands of RGB cables (HQ), and no scart switch in between, just in case, but I still get the issues.. The horizontal shimmering is not much, but clearly visible.. But the vertical scrolling ...

I measured on the original clk source for the PAL signal and its 53.2040 (rounded up somehow from 53.203425 I guess?)

Hmm tried to get some measurements while the test CD is running but its not the easiest to do since its quite cramped when the cd unit is mounted but here are some shots with the scope.. it looks a bit off indeed... since it should show 53.693175 MHz on NTSC and 53.203425 MHz on PAL.

NTSC = 53.6900 ...

I have a SCPH-9002 (PAL) that I installed a DFO in. (and a modchip)

When I run the scroll test I get some microstutter every 1-2 seconds when scrolling the gray tiles vertically in some of the speeds, and even some "shimmering" in the trees in the background of the horizontally scrolling sonic ...