I am currently working my way through the examples but cant seem to find a particular way of sending data from a PC to the Adrunio which will switch on 8 digital outputs.
That's because you get to define what to send and what to do in reaction to that value/data/string appearing.
I would like to be able to send instruction as a Byte from the PC with some sort of identification attached which would be stripped from the data before being transmitted.
If you are going to strip off the ID, why send it?
Ideally I want the unit to serve my project using multiple comm send and receives for data aquisition.
You need to elaborate on this. What is "my project"? Does "using multiple comm send and receives" mean more than one connection to the PC, or does it mean doing the send/receive operation more than once?
How does sending a byte from the PC to the Arduino result in data acquisition?
Also i keep reading that i cant use pins 4 & 5 as they are dedicated to Serial Comms.
Take whatever you are reading this crap in to the nearest shredder.
Pins 0 and 1 are used by Serial. Other pins, clearly labeled on the board, are used by Serial1, Serial2, and Serial3. If you don't need those pins for those purposes, you can use the pins for other things.
Of course, if you want to communicate with the PC you HAVE to leave pins 0 and 1 alone.
Im using the Mega is this still true
I guess it is. You told us you are.
incidently the pin map starts at pin 1 not 0 WHY!
What pin map? If it's in the same material that says you can't use pins 4 and 5, it's rubbish.
the functions dont even coincide as pin 1 is a PWM pin?
What functions? Pin 1 is NOT a PWM pin.
and no not the famous Microsoft suggestion
Well, you do need to be smart enough to figure out what's rubbish and what's true. You're not doing too good, so far.
But, you are trying, and that's good.