Mobo or Processor?

here's the problem, my dad has a computer from Time which has started having problems with programs crashing randomly.
the specs are:
AMD Athlon XP 2800+ (i think)
nVidia nForce 2 Motherboard (integrated graphics)
2x256MB RAM
i thought it was the memory and the SuSE memory checker seemed to back this up. the computer was only detecting 384MB of RAM and the memory checker showed hundreds of errors. wanting to know which stick was broken i put one in and tested it separately. each RAM stick was only showing 128MB but had no errors apart from that in whatever slot i put it in. it was when i used two RAM sticks that the errors started showing. so does anyone know which part is broken? the motherboard or the processor (which i think has a memory controller but i'm not sure)

System may be showing 384 MB RAM, because 128MB may be used up by the graphics card. So that part is ok.

But, if you put a 256MB stick on its own and it shows that only 128 is present, there is definitely a problem with your memory controller, which is located on the motherboard. I would say that your motherboard is broken or faulty in this case.

note: Athlon XP series of processors don't have inbuilt (on the processor itself) memory controllers, niether do pentiums. Only Athlon 64's have them.

ok. i'd heard that athlons had inbuilt memory controllers and assumed that they were all like that. thanks for clearing it up, now i can get my dad to get a new mobo and graphcs card. :D