dan@s3dawn.ARPA (Dan Peterka) (07/15/89)
Has anyone had the following 'weirdness' with Apple's 8 bit video card? : EQUIPMENT: Mac IIcx Expanded 8bit video card Sony 1302 multisyncing monitor Shielded and unsheilded video cables Using an unsheilded video cable everthing works just fine except that the colors on the display are 'off' (kinda greenish). I expected this behavior as it is identical to what we experienced on a similarly equipped Mac II. The solution for the Mac II was to obtain a shielded video cable. This was promptly done on the IIcx with the following result: PROBLEM: The Sony doesn't appear to sync up properly to the video board. The displayed resolution goes way down (characters are much larger than usual and the screen image goes way off the display; the disk icon and trashcan are off the display). There is also CONSIDERABLE flickering in the display. On occasion, the Mac WILL sync to the appropriate resolution, but the flicker persists. Even stranger still is the fact the monitors CDEV in the control panel gives only 16 and 256 color options - the 2 and 4 color options don't get listed. The video board is indeed the problem here. Swapping boards with the Mac II produces the same problems on that machine. QUESTION: Is my video board defective? (remember it works with the unsheilded cable!) Or is this perhaps designed into the newer video boards (it looks much different than the older board in our Mac II) to prevent people from using multi-sync monitors, thereby gauranteeing sales of Apple's monitors? My gut feeling is that the video sync signal is perhaps off by some small, but usually acceptable amount which causes the 1302 to sync incorrectly. The unshielded cable perhaps screws up the signal (I'm an ME by training - what's EE lingo for screws up?) just enough so that it squeeks by. My next test will be to see if the problem persists with a single sync monitor (no Apple monitors around here), but we are waiting on that. _______________________________________________________________________________ Dan Peterka S-Cubed PO Box 1620 dan@scubed.com (619) 587-8338 La Jolla, CA 92038