From: doctor@ptolemy.arc.nasa.gov (Terry Fong) Subject: Re: TECH: Homebrewing an alternative VideoSplitter? Date: Thu, 11 Jun 1992 05:04:01 GMT Organization: NASA/ARC Information Sciences Division In article <1992Jun10.151453.20750@u.washington.edu> Hans.Jense@fel.tno.nl (Hans Jense) writes: >So far, I've received the following replies to my question about >a cheaper alternative for an SGI VideoSplitter: Okay Hans, Have I got a solution for you! What about simply putting the VGX into stereo mode (via setmonitor(STR_RECT) in GL or via /usr/gfx/setmon STEREO). This will produce a 120Hz RGB signal with sequential fields, each being 1280x492 (note that due to the vertical blanking in stereo, you don't get 512 vertical pixels, but only 492). Then it is a simple matter of building a video switcher that alternates output channels every other vertical sync pulse. This is, essentially, how the StereoView LCD glasses are used (i.e., the crystals alternate on each vertical sync pulse to sequentially display each stereo sub-field). Of course, you will still have to figure out how to convert the 60HZ interlaced RGB signal to NTSC composite or component. If you don't have a scan converter which can be switched at 60HZ, perhaps you should check out some of the single-chip converters made by Brooktree. Cheers, -Terry _______________________________________________________________________________ "When I come home to you, San Fran- | Terry Fong cisco, golden sun will shine on me" | NASA Ames, M/S 269-3, Moffett Field, CA -- "I Left my Heart in S.F." | (415) 604-6063, FTS-464-6063