Page 1 of 1

Strange distortion on 32X

Posted: Tue Sep 09, 2008 8:32 pm
by mic_
If there's anyone here who has a 32X and some means to run code on it, it'd be interesting if you could run this and see what you get.
On my (PAL) 32X + Megadrive 2 I get some weird distortion on the first 16 and the last 48 (give or take) pixels of each row. This obviously doesn't happen in Gens or Fusion.
Basically what I'm doing is:

* Generate one frame of data in SDRAM
* Wait for the next vblank
* Flip the FS bit
* Copy SDRAM data to the framebuffer (in groups of 16 bits)

Posted: Thu Sep 11, 2008 10:22 am
by TmEE co.(TM)
I got an internal server error...

Posted: Thu Sep 11, 2008 11:13 am
by mic_
My web host behaves weird sometimes. Try this link

Posted: Thu Sep 11, 2008 12:29 pm
by TmEE co.(TM)
For some unknown reason this did not work on my highly modded MD2 + PAL 32X, it did work using my MD1 and other unmodded MD2, but my 32X is modified to accept the centered screen sync signal of my modded MD2 so with other systems there's rolling scrolling screen, thus I can't say anything about the distortion (as the whole screen is ditortion :P)... I'm gonna do some unmodding and check again.

Posted: Fri Sep 12, 2008 1:39 pm
by TmEE co.(TM)
Came out that the problem was in the dead cartslot of my MD2...

I could not see any distortions either in 50 or 60Hz and with PAL or NTSC master clocks. Works perfectly.

Posted: Sat Sep 13, 2008 7:58 am
by mic_
That's weird. Maybe it's my 32X then, it's been having trouble generating a stable signal lately. When I start up the Megacart the colors in the menu are either way too dark or way too bright (it works fine when using it on the Megadrive only).

Posted: Sat Sep 13, 2008 8:37 am
by TmEE co.(TM)
32X does not even have capacitors in it which could cause such anomalies upon being close to dying...

Posted: Sat Sep 13, 2008 9:55 am
by mic_
Well, I don't have the metal retainers, and the 32X seems quite sensitive to movement so that might have something to do with it. It used to work fine without them, though.

Posted: Sat Sep 13, 2008 7:56 pm
by TmEE co.(TM)
I don't have any such thing on my 32X, just the device wobbling in my MD2 cartslot... no problems (if you don't count the cartslot issues of my MD2...)

Japanese units have no RF shields or related things at all BTW