Commodore 1084S-D2 -> PC Engine IFU problem.

[Ex_Mosquito]

Hi guys I need help. I just made a DB9 -> Scart adaptor for my Commodore 1084s monitor but for some reason when I try and centre the screen using the ‘h-phase’ adjustment I get a wavy image (1st pic), but if I adjust the screen off-centre to the left it has perfect geometry with no wavey effect (2nd pic) this is the pin out I used (3rd pic) Any ideas? Btw, this is being used via an IFU briefcase unit with RGB amp PCB installed. I remember using my friends CoreGrafx2 that was RGB modded with ONLY audio transistors and I didn’t get this issue, but with a professional PCB amp in my IFU unit I’m getting this issue, could that be the problem somehow?





My Megadrive works perfectly fine.


Thanks! Mark.

[buttersoft]

Is the sync line amped or not in your setup? And is this the opposite to your friend's setup?

[Ex_Mosquito]

Heya. I actually managed to fix this issue yesterday, I was going to update today. It turns out the IFU was wired up to ‘composite sync’ which was fine for my Sony Trinitron but the 1084 didn’t like it. Apparently the IFU needed to be wired to the ‘sync’ and not ‘composite sync’ :/

[buttersoft]

Yeah it was always going to be a sync issue, though i'm surprised by the exact result. Glad to hear you sorted it, i'm grabbing an IFU-30 soon and I have a Philips 8833, cousin to the 1084s

[Ex_Mosquito]

Heh yeah, I could’nt believe it was such a simple solution... crazy. Ah, the Philips 8833, that was the monitor my local importer used for their Japanese MD back in 1990, amazing monitor Super Real Basketball used to be on loop on that monitor. From memory It had a slightly sharper image than the softer 1084s, great monitor for 15Khz RGB, one of the best.