ross@cattell.psych.upenn.edu (Ross Porter) (10/09/90)
We have an interest in using PCs to display extremely simple images for extremely short durations (20-100msec). Our problem is that we need to have greater control over image duration than that allotted by the ~17msec period of a standard 60Hz raster monitor. To get these image characteristics, we are currently using vector monitors . We would be perfectly content to continue, if there was such a thing as a PC vector display controller. We are currently using MegaTek vector display controllers attached to some old DEC Q-bus based systems (LSI-11/23 type machines). The one, perhaps naive, raster idea that has been put forth is to use only a small section (i.e. 200x100x2) of a high-res display. Consider the ~50,000 pixel/msec ideal speed of a 1024x768 non-interlaced 60Hz display. If we applied that 50,000 pixel/msec speed to a 20,000 pixel sub-section, we could theoretically update in well under 1ms. We realize that for most applications the frame rate is not the limiting factor of graphics performance -- BLIT speed or whatever is much more important. However, for our purposes (psychological research), the frame rate may very well be the limiting factor. We are using extremely simple displays (e.g. five 1-inch characters) that are completely pre-determined and need to be displayed no more frequently than once every three seconds (20-100msec duration per display). So, our questions: Is this sub-section idea THEORETICALLY possible? Does hardware exist that will allow this? If we could do this with an SVGA board, we'd be estatic. We're perfectly willing to dirty DOS programming, as the experiment code will NEVER be run in a multi-tasking environment. Any advice you can offer would be appreciated. Any pointers to display controller manufacturers would that might know some of these answers would also be appreciated. Thanks, Ross ross@cattell.psych.upenn.edu