mil@mendel.acc.Virginia.EDU (Maria I. Lasaga) (08/19/90)
Does anyone know how to determine when the vertical retrace is at the top of an EXTERNAL monitor that is connected to an SE via the 68000 Direct Slot? We can find no documentation on this whatsoever. There is documentation in IM on how to associate a VBL queue with external monitor that is connected to a mac II, using the Slot Manager, but we cannot use the Slot Manager with the 68000 Direct Slot. Determining when the vertical retrace is at the top of an internal monitor of an older mac is easy, too, by just keeping track of when the tickcount changes. Unfortunately, we need to use an external monitor, and we only have an SE available for use. Yet it seems that the VBL queue of an SE is associated with its INTERNAL monitor, and so we cannot simply determine when the tickcount changes, since that only tells us when the vertical retrace of the INTERNAL monitor is at the top of the screen. Any help with this problem, suggested references, etc., would be greatly appreciated. (We even purchased the book, "Designing Cards and Drivers for the Macintosh Family," but there was little information in it about the 68000 Direct Slot that we could use.) -maria lasaga --------------------------------------------------------------------------- Maria Lasaga Dept. of Psychology Gilmer Hall University of Virginia Charlottesville, Virginia 22903 mil@virginia.bitnet ---------------------------------------------------------------------------