Yeah, I've seen the 9" POS monitor done. It's electrically much simpler, but mechanically more difficult to install with minimal modification to the casing. I figured if I want to do a lot of mechanical modification, I might as well retrofit an 8.4" SVGA color LCD - which I may do if this idea doesn't pan out, because my motherboard has an LVDS connector.
It's possible my experimentation that resulted in what appears to be a grayscale raster may have been just operating the existing video amp on the fringe of its limits since it didn't self-destruct. The Classic video amp doesn't have the IC inverter that the Plus and older classic Macs have. I will have to see if I can get a schematic of the SE/30 grayscale card. I've seen photos of it and it looks fairly simple.
I think the biggest problem will be sync. I've still not verified that all that needs to be done to support a higher resolution is to increase the horizontal deflection voltage. It seems that's all that's necessary to get VGA out of a color Classic, but it could be the tutorial I read didn't get very detailed. Not having a schematic of the Mac Classic analog board makes it more complicated to even figure out how to raise the voltage. As for the sync signal itself, I'm not sure how complicated that would be. Isn't it going to be TTL and either negative or positive triggered? If so, I think I would be able to just simply invert the sync signal as necessary.
My goal would be that the built-in monitor could work as the primary with no external monitor connected, but for practical purposes, an external monitor would be primary and the built-in B&W would a secondary that I could throw a clock, calendar, and other things onto. In that case, I don't think 640x480 would be bad at all.
It's possible my experimentation that resulted in what appears to be a grayscale raster may have been just operating the existing video amp on the fringe of its limits since it didn't self-destruct. The Classic video amp doesn't have the IC inverter that the Plus and older classic Macs have. I will have to see if I can get a schematic of the SE/30 grayscale card. I've seen photos of it and it looks fairly simple.
I think the biggest problem will be sync. I've still not verified that all that needs to be done to support a higher resolution is to increase the horizontal deflection voltage. It seems that's all that's necessary to get VGA out of a color Classic, but it could be the tutorial I read didn't get very detailed. Not having a schematic of the Mac Classic analog board makes it more complicated to even figure out how to raise the voltage. As for the sync signal itself, I'm not sure how complicated that would be. Isn't it going to be TTL and either negative or positive triggered? If so, I think I would be able to just simply invert the sync signal as necessary.
My goal would be that the built-in monitor could work as the primary with no external monitor connected, but for practical purposes, an external monitor would be primary and the built-in B&W would a secondary that I could throw a clock, calendar, and other things onto. In that case, I don't think 640x480 would be bad at all.