Hi folks! Im testing my Everdrive cartridge on my Sega TeraDrive and Im noticing a few things. When I use the TeraDrive in RGB mode plugged into the monitor I see the top area of the screen is all sketched to the right and it trembles a lot, like a frequency issue. This happens at the menu and with games. Anyone know if I plug the Everdrive into a MegaKey this issue will be solved? Thanks!
Have you tried a regular game cart yet to see if it shows up there? It could be signal interference since RGB is finicky. Maybe the C-SYNC is screwed up or something like that. The Everdrive Mega and MD have Mega Key built into them. Hardware based Mega Keys.
I tried Pier Solar and other games yesterday and the problem persists. Maybe is something with the motherboard? When I use the VGA under PC mode it works fine.
Try a different cable or monitor if possible. If the problem persists, then there's something wrong with the MD hardware. Tried the composite output yet to see if it is there too? I doubt if it will but if there's something wrong with the RGB output, I think it would screw up the composite video encoding too.
Maybe the Teradrive monitor just isn't top notch in 15khz rgb mode, or it is simply old (we are talking 22 year old hardware here).
I will try a different cable, Im using a flatscreen LCD that accepts 15khz. The composite is just fine, no troubles on it, also the RGB works well on PC mode.
Im using a modern LCD that accepts 15khz (I plug in MSX thru RGB, Amiga thru RGB and is working well). I will try a new cable.
The MegaDrives 15KHz timing is slightly different than other systems. So I wouldn't be surprised if it's an incompatibility.
That makes sense, since I never saw anything documented about this its hard to say. Anyway, do you think a scandoubler (15khz to 31khz converter) might work for this? Thanks!
I'm not sure. An older thread here a guy was trying to do just that with with a model 1. He had no success. My best suggestion is to try the board, follow some guides on adjusting the RGB lines with caps and resistors, and use composite video for sync with a sync stripper in between the Megadrive and the scan doubler. That seems to be the most likely way it will work.
I guess I found what is happening here. The problem is at the SYNC signals from TeraDrive, my monitor has some troubles with some 15Khz SYNC signals and some old consoles/computers need a LM1881 sync stripper as mentioned on this website: http://www.mmmonkey.co.uk/composite-sync-stripper-lm1881/ Lucky me I have one of these assembled, I use it on my MSX Turbo-R GT RGB output to get a nice screen on this LCD monitor, I will try to use it and post here if it works. It can be used with a scan doubler in order to achieve the 31khz signal the modern LCDs uses nowadays. thanks!
The Megadrive already outputs native sync and doesn't need a sync stripper, so I'd assume the Teradrive does too.
True but it seems to cause many issues with a lot of monitors. Composite Sync seems to be a bit more compatible.
Composite sync IS the pin dedicated to sync. I think your confusing Composite video as sync, which isn't what I'm referring to. I quite know the pinout of the AV port on the Megadrive, I made a Component video adapter for it, and used composite sync, which is a clean H and V sync combined, hence composite sync.
