I was using 10.04, upgraded to 12.04 15 days before. My system specifications are:
512 MB Ram ( 2 slots each of 256 MB 184pin DDR DIMM RAM ) i686, AMD Athlon ( 1150 MHZ ), without graphics card.
I am a normal user. I want to upgrade my system ( I don't want to buy a new one ) to 2 GB RAM ( 1+1 GB). There is a slot for AGP3 graphics card. But Is Graphic card necessary for Ubuntu 12.04 ?