Unfortunate. The strange thing is the projector syncs fine over s-video (although that was an NTSC cube, not the current PAL cube), but not over HDMI (via PAL RGB output). But I don't know if the timing is really the same. This thing is putting out what I assume is PAL60 RGB at NTSC resolutions? Would that be different than straight NTSC RGB (if I had a gcvideo)?marqs wrote:GC has fixed pixel clock, so its refresh rate can only be changed by modifying number of scanlines and/or scanline length. Playing around with the numbers you provided, you end up to following parameters to get claimed refresh rates:
GBI LL:
27000000/(858*526) = 59.8261Hz
GBI ULL:
27000000/(866*522) = 59.7276Hz
That also explains why ULL is not as compatible since many displays will sync only with 525+-1 -line signals. On those displays where ULL works, I recommend setting H. samplerate to 866 in adv. timing for best quality (I'll add this to wiki soon).
A quick test shows that connecting the GARO's VGA output to a different VGA display didn't result in the OSSC syncing, only connecting the GARO directly to the OSSC.marqs wrote:Sounds like grounding issue to me since AV1 and AV3 inputs do not share any logic. GARO's outputs are probably just split without buffering (I guess they are not meant to be used simultaneously) so gain will be lower since R/G/B are terminated twice.
I checked the GARO's ground SCART pins, and found that pin 14 (data ground) and 17 (composite/sync out ground) were not grounded (not connected to the GARO's ground plane). I soldered some wires in place to connect those two pins to ground, but it didn't make any difference. I also confirmed that, with only the SCART cable connected, I see continuity between the OSSC and GARO ground plans (tested from GARO power socket ground to OSSC VGA connector shell).
Both the GARO and the OSSC are connected to the same power bar via AC adapters, and don't use the same power supply (5v for OSSC, 12v for GARO). Could any of this be a problem? Could it be a ground loop?
In the mean time, I have a workaround, even if it does add an extra cable to an already super crowded area. I think my next step is to contact beharius and see if he has any thoughts.