2 dual channel question

[redxdeath]

i was wondering if i could use 2 dual channels

A blue slots 1,2: patriot 1GBdc
B black slots 3,4: bro's old dual channel 512MB 2x256


im was about to buy a patriot 1gb dual channel ram to upgrade my computers 256mb of ram and my brother is getting rid of his dual channel 512mb[if not i'd stick with the patriot and give the dual channel 512mb to my cousins,etc]

my computers mobo is:

ASUS Amberine M(A8AE-LE) mobo pic :

plus i have a sckt939 sempron64 3400+ Palermo @2GHz

 

[Nitestick]

well for starters dual channel is dual channel. 2 dual channels would be 4 channels. to run 4 sticks in dual channel they would all have to be identical but honestly i would not reccomend it. you are best off with only 2 sticks