landru@stan.com (Mike Rosenlof) (09/13/88)
Hello, world. I'm writing a driver for the Sun CG3, and don't really want to go through pixrect. Can somebody give me a few pointers on this graphics device? I think I understand everything pretty well including the function of the ROP processors, but in the file '/usr/include/pixrect/cg2reg.h', I am a little confused over the 'ropcontrol' in the frame buffer descriptor. It's declared as a union of the 'normal register access' rop control registers and offset by 2048 bytes, a 'for pixmode src reg prime byte xfer loads alternate src register'. Any insignt to the workings of this alternate would be most helpful. thanks!