Samurai Shodown (PAL) pixel garbage?

[Former user]

Original [issue 193](https://code.google.com/p/genplus-gx/issues/detail?id=193) created by gora.patrick on 2011-10-29T15:30:23.000Z:

Hi there,

i just got a copy of Samurai Shodown for my megadrive where i get some pixel garbage lines on the screen (in character select + ingame). it doesn't happen in any emulator (like genplus gx ;)) so i'm asking if my cartdige is damaged or does this happen for others as well on real machine? tried it on both my Megadrive 1 and 2. Happens with RGB as well as with a RF unit. i attached a video showing the pixel garbage.

http://www.megaupload.com/?d=2N1L6ZJ0

[Former user]

Comment # 1 originally posted by ekeeke31 on 2011-10-29T17:57:49.000Z:

I see nothing wrong. Garbage pixels are generally artefacts of Color RAM writes during active display. In this case, written color value interferes with the value read by the VDP when rendering current pixel.

This is generally not emulated because exact behavior is still not fully understood. I think only Retrocopy has some attempts to emulate it but it's not 100% accurate and much more noticeable that with real hardware. Anyway, most games don't do this and change color palettes during hblank or vblank.

[Former user]

Comment # 2 originally posted by gora.patrick on 2011-10-30T01:05:08.000Z:

Ah ok. thank for the explanation. i was just wondering, because it's so visible in the center of the screen. and not somewhere off the picture.