Thanks for your reply Craig. And yes i HAVE been doing some research on all the above. However, i'm still having trouble understanding what the difference is between all these different models. My requirement is to "compare the 8051 processor(small) and Power PC processor(large)-where the processor applies to a FAMILY of processors, you are required to describe the common properties across the family and chose one variant to answer more specific questions". Now what i don't understand is this. It just says the 8051 processor... but there are so many processors. What does it mean by FAMILY of processor? does this mean, the MAIN characteristics of all the different models of 8051?

Sorry, bout my earlier post... it should have ONLY been these topics below which i needed help on. I forgot to delete the other ones after the copy and paste...

1)The cost of the processor in single quantity and in bulk .
2)The clock speed of the microprocessor .
3)The Register structure.
4)The power consumption.

Thanks again..