I see that X servers can be set to run at 8,16,24, or 32 BPP. (also 2 and 4 but that's yuck!).
I know that the 8 bpp mode uses a map table to select 256 out of 2**16 or 2**18 colors, assuming that the card has 3 6 bit dac's, one for each color. In 16 or 15 bit mode the access to the dac's is direct. 5 bits are used for each dac, with the lsb set to 0. In 16 bbp mode the extra bit is given to the green dac. In 24bpp mode 8 bit dac's are used, 8*3=24 bits. What happens in 32bpp?? I do not believe that video dac's are available wider than 8 bits. If they are, are 3 10 bit dac's used, with the extra 2 bits thrown away? Or is a 12 bit dac used for the green???? Or is this only a maping thing, 24 bits are used, and a whole byte is thrown away, but using 32bits per pixel cleans up the dma access some how? == Amateur Radio, when all else fails! http://www.qsl.net/wa2mze Debian Gnu Linux, Live Free or ..... _________________________________________________________ DO YOU YAHOO!? Get your free @yahoo.com address at http://mail.yahoo.com