SYM Electronics

Look how to know its your RAM IS DDR1 or DDR2 or DDR3 by loooking it ???
DDR1 RAM always have 184 pins which means their pins and bigger in rectangular form than DDR2 or 3 so we can know its DDR1.
and DDR2 and DDR3 have same 240 pins but how can we know which is actual Type ???
so The mouth of DDR2 mouth/notches always lies on the right side of the center ..
and DDR3 Mouth/notches always lies on Left side of the Center like in the figure look .....

Inverter digram 600/800