> Does anyone here know if the VGA cards prevent you from controlling > the DAC durinng the blanking intervals? Are the blanking intervals > implemented in hardware or in software?
Generally, video cards stop squirting bits during the blanking intervals, which are implemented in software. This lets the adjacent rows of the frame buffer be next to each other in the memory that the video hardware is scanning its way through. However, the timing of the blanking intervals can be controlled with a fair bit of detail. These are those terrible X config "modeline" values that can blow up your monitor if you set them wrongly. There will be *some* blanking interval, but it can perhaps be very short and can perhaps occur at an interval that won't often affect your signal. It would be great if video hardware had a mode that turned off this foolishness and just kept scanning out a section of RAM, raw. This would even improve refresh rates on things like LCDs that don't have to move an electron beam back across the screen during the "horizontal retrace" time. But few video chips probably do. John _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio