harrison@adm.csc.ncsu.edu (Lou Harrison) (05/01/91)
Well, I now can do stereo (sort of) on my PI. Let me tell you how. I have the Red and Blue channels running straight through from the PI to the Tektronics SGS 620 60/120Hz monitor. The green channel (with the sync) goes to the video in of the StereoGraphics GDC-3 box. Composite Out from the GDC-3 goes to green on the tektronix monitor. The GDC-3 is responsible for converting the input 60Hz signal to an output 120Hz signal to send to the monitor. The drive output from the GDC-3 goes to either the Frame sync on the monitor (to drive the shutter) or to the crystal eyes emitter, depending on whether I'm using the passive or active glasses. With the bypass pushed in on the GDC-3 everything should be 60Hz, with it out, the monitor switches to 120Hz. The trick is to not tell the PI that it is in stereo mode, the GDC-3 does all the work, and if the PI tries to do stereo too... what a mess! Everything seems to work fine, but... Somewhere inside the GDC-3 the green with sync signal becomes (nothing) with sync signal. The green channel gets stripped off. Effectively, I can do stereo, but only in purple! I thought about trying to link the green back in with a tee to the composite out from the GDC-3, but I don't want to set up a feedback loop. This has gone beyond my level of technical competence. Any ideas? As always, thanx in advance, Lou Harrison harrison@adm.csc.ncsu.edu