Does the Quadra 800 put out any kind of separated sync?

[dankcomputing]

I have here a Quadra 800 that *only* puts out sync on green no matter what adapter I use. I also have a iisi here and that will put out csync on the hsync line if I configure the adapter right. That same adapter, configured identically, is not putting out sync on the sync lines when plugged into the Q800. I looked on the schematics and the sync lines are definitely present and hooked up to the appropriate custom chip. Does anyone else's Q800 act like this, or do I have a hardware problem, or did Apple just force this model to put out sync on green only?

 

[eharmon]

I can try to dig up the docs this weekend, but that sounds familiar -- I think there was a race condition in the system initialization that could cause it to stick in SoG mode.

I believe that was fixed later. What OS are you running? Do you have the Quadra monitors extension installed?

I think for older OS, sometimes installing the Basic Color Monitor extension works around the issue. You just have to boot it once with the extension to snap the machine out of SoG. Alternatively that's what stuck it in SoG and zapping PRAM can fix it...can't quite remember.

 

[volvo242gt]

Remember that the IIsi and the Wombat board machines (Centris 650, Quadra 650/800) use different video circuitry as well. Which adapter are you using? If it's a Sony MacView LX, try putting it into VGA mode. That may cause it to work normally. I know that when I had said adapter set up for a 19" monitor (Dell 1908FP) and connected to the Centris 650 I had at the time, it definitely was stuck in SoG mode. When I reset the adapter to VGA mode (two middle dip switches on, rest off) and used it with my old LC III, video was normal.
C650:

LC III:

 

[eharmon]

I found the docs, it's System Update 3.0 that corrects the issue with the Basic Color Monitor and some VGA monitors:

• Corrects color problems with the Apple Basic Color monitor on Macintosh Centris and Quadra computers. (NOTE: If Hardware System Update 1.0, Hardware System Update 2.0, or System Update 2.0.1 extensions or the Basic Color Monitor extension are already installed on your computer, this update replaces them. The 3.0 update removes the Basic Color Monitor and the ADBReInit extensions and replaces them with a System Update 3.0 extension.)