Archive for January, 2016

VDMA tests

Posted in Uncategorized on January 3, 2016 by pcedev

Ok, so I confirmed what others have tested: vdma is somewhere between 81-85 WORDs per scanline in 5.37mhz mode. So in 10.74mhz mode, that’s 330+ bytes per scanline. The more you clipped active display, the more bandwidth you get for vdma. I did a 209 line display and was able to transfer 17.6+ kbytes during vblank. This is perfect for the bitmap mode and all that I’ve talked about in that regards (free buffer clear, free transfer for double buffer system, etc).