White specks when loading - Genesis Model 2 - Normal?

[evil_ash_xero]

I have a Genesis Model 2 and a Mega Drive Model 2. I've noticed that with a number of games there will be white specks when loading a stage. Sometimes a straight line of them, at the top of the screen while the screen is black. Sometimes a little bit in the game, while it loads some text up, like "GO" or whatever. This is especially noticeable in Streets of Rage 2 when the screen is black between stages, or the aforementioned "GO".
It's not really during the game, unless it's loading a new section of a stage. And it just lasts a second.
Some games don't have this at all.

I am using an EverDrive, and using RGB to Component converters. I thought maybe it was Voultar's video chip that I got my Gen modded with, but my unmodded (at the time) Mega Drive Model 2 did the same thing.
It has these very regularly when I go to the menu of the EverDrive, during a game, and going to the menu or whatever.

I have tried with normal carts, and they were exactly the same, in the same exact places.

Is this just a Genesis 2 thing? Unfortunately, I don't have any other ones around that have composite output, so I can't really check.

My systems are kinda modded out, with Voultars RGB chip, region switch, and CCAM mods. So, I'm just wondering if someone has a virgin Genesis Model 2, that is hooked up the same way and has this quirk?

A good spot to see if this happens, is when you start Sonic the Hedgehog 1, and right underneath "Sonic Team Presents", you'll get a little line of white.

[Kez]

I see this a lot between stages when playing SOR2 on my Mega Drive 1. I always figured they were CRAM dots or something similar.

[evil_ash_xero]

I see this a lot between stages when playing SOR2 on my Mega Drive 1. I always figured they were CRAM dots or something similar.

Where on the screen do they pop up?

[Kez]

Here's a badly recorded example you should be able to see if you download the file (I think it's compressed if you view it in the browser):

https://www.dropbox.com/s/mrcybdj7er0m2 ... 012932.mp4

[evil_ash_xero]

Thanks. That's exactly what I'm talking about.

You have any mods? Is this going thru RGB or Composite?

[Sumez]

Not too familiar with the MegaDrive, but without knowing too much about it, this sounds like artifacts that would usually happen due to the timing with which software writes to video memory. Probably stuff that wasn't visible "back in the days" due to CRT overscan, so no one cared? Whenever I see stuff like that, my brain just completely ignores it.

MegaDrive games especially seem to have a pretty bad habit of just leaving huge streaks of garbage in title screens, etc.

[Kez]

You have any mods? Is this going thru RGB or Composite?

I have done an RGB bypass but I am pretty sure it always happened.

this sounds like artifacts that would usually happen due to the timing with which software writes to video memory.

Yeah, that's my thinking as well. There is some info on them here.

[evil_ash_xero]

Ah, OK. Thanks for the info.
I had one unmodded one, that I sold recently. And I noticed that it did it when I reset the EverDrive, and I noticed it in Strider. I just didn't experiment around much with it.

But it seems just like a Genesis thing.

That being said, I wish some other people would chime in. I know you guys are playing these machines time to time.

[Herr Schatten]

But it seems just like a Genesis thing.

Not really. There's plenty of it on the Master System, too. It happens whenever you write data to the color RAM during active display. As it's usually near the screen edge, it used to disappear in the overscan area on CRTs, on modern displays it suddenly is in plain sight, though.

[mikejmoffitt]

This is a "Genesis thing" - and actually, it's present in a lot of Arcade games as well. The NES will do this if programmed in a particular way, even. It's just an artifact of how Palette RAM arbitration works between the two sources of address control (CPU, or the PPU's scanout). Whether or not this happens on-screen, or off-screen, is a matter of timing, and is up to the programmer.

Fantasy Zone II DX does it pretty prominently when the bottom navigation bar fades in and out, or during scene transitions. I think some Konami arcade titles do it too. CPS2 hardware forbids it, in some nice foresight by Capcom.