edit: I tested the sync combiner RGB cable on another Dreamcast and it works perfectly. But I still have no green signal on the first Dreamcast, and I can't determine why. Jump to current post here: viewtopic.php?p=153976#p153976
Hey all,
As you might know, the Dreamcast can output 240p/480i over RGB SCART and 480p over VGA. So people on the net have posted sync combiners that allow you to use the VGA signal over SCART, and force 480p over RGB with composite sync. I decided to try the following:
http://dcemulation.org/?title=Dreamcast ... ster_Cable
I'm using the XRGB mini Framemeister. When I tested it, the image is stable on the screen. So that suggests to me that the new composite sync is working as it should. The problem I have is that the red level is WAY too intense.
I snapped a couple of crappy cell phone pics. My cell phone camera picked up on the red a lot, it doesn't actually look this red in person, but it's enough to get the idea...
White areas look pink. For example, the start up screen that is mostly white, I have a very pink screen. When I turn the red level down, it makes it clear that red is too intense, but that can't be used to fix the problem...
(Again, my crappy cell phone camera picked up on the red too much, but this still give you an idea)
So I know that 480p over SCART is not standard, and as I understand it, it's pushing the limits. But numerous sources on the net claim that this works (here's another source). Can sync effect color intensity? Could the sync combiner circuit that I'm using be causing the problem?
I double and triple checked everything. I confirmed that the R, G and B lines a wired up to the correct pins on both ends of the cables. I checked for shorts to ground on the RGB lines. I checked to make sure the polarity of all the caps are correct, and the diodes are facing the right way.
Pins 6 and 7 on the Dreamcast's multi AV port are used to select modes. Ground one for RGB 480i mode, ground both for VGA 480p mode. Some sources say to ground pin 6 and switch pin 7 between ground and floating, other sources say vise versa, so I don't think it matters. I grounded pin 6 and switch pin 7. I confirmed that when my switch is in one position that a (VGA compatible) game loads in 480p, and when the switch is in the other position the game loads in 480i. Doesn't make a difference though, I still have a very red screen either way.
Unfortunately, the cable that I used didn't have enough wires to include the Dreamcast's composite sync signal. So I have no way of bypassing the sync combiner circuit to see if that's the problem.
Thanks for any input.
Hey all,
As you might know, the Dreamcast can output 240p/480i over RGB SCART and 480p over VGA. So people on the net have posted sync combiners that allow you to use the VGA signal over SCART, and force 480p over RGB with composite sync. I decided to try the following:
http://dcemulation.org/?title=Dreamcast ... ster_Cable
I'm using the XRGB mini Framemeister. When I tested it, the image is stable on the screen. So that suggests to me that the new composite sync is working as it should. The problem I have is that the red level is WAY too intense.
I snapped a couple of crappy cell phone pics. My cell phone camera picked up on the red a lot, it doesn't actually look this red in person, but it's enough to get the idea...
White areas look pink. For example, the start up screen that is mostly white, I have a very pink screen. When I turn the red level down, it makes it clear that red is too intense, but that can't be used to fix the problem...
(Again, my crappy cell phone camera picked up on the red too much, but this still give you an idea)
So I know that 480p over SCART is not standard, and as I understand it, it's pushing the limits. But numerous sources on the net claim that this works (here's another source). Can sync effect color intensity? Could the sync combiner circuit that I'm using be causing the problem?
I double and triple checked everything. I confirmed that the R, G and B lines a wired up to the correct pins on both ends of the cables. I checked for shorts to ground on the RGB lines. I checked to make sure the polarity of all the caps are correct, and the diodes are facing the right way.
Pins 6 and 7 on the Dreamcast's multi AV port are used to select modes. Ground one for RGB 480i mode, ground both for VGA 480p mode. Some sources say to ground pin 6 and switch pin 7 between ground and floating, other sources say vise versa, so I don't think it matters. I grounded pin 6 and switch pin 7. I confirmed that when my switch is in one position that a (VGA compatible) game loads in 480p, and when the switch is in the other position the game loads in 480i. Doesn't make a difference though, I still have a very red screen either way.
Unfortunately, the cable that I used didn't have enough wires to include the Dreamcast's composite sync signal. So I have no way of bypassing the sync combiner circuit to see if that's the problem.
Thanks for any input.