An expanded version of what I said before
We are building everything on breadboards, but a pro would use a circuit making program and a device that would etch a circuit board. Snce we are building basically an over--glorified calculator (we are basicall replaying the history of how computers evolved into PCs, except we are only uusing an Arithmatic Logic Unit, and not a MicroProcessor).
Our task is to design and build a "computer" that stores the numbers 2,3,4, and 5 in RAM, and then adds themtogether to get 14. Seems easy, but the ALU can only add two numbers at a time, so we have to build in a looping capability, our "Programing Language" is incredibly basic, we have simple commands that are 8bit binary numbers, to distinguish from our data we are making all the commands be in the form 1000 0xxx, where the xxx represents one of our 8 commands. Then we have to devise a circuit that will interpret these commands and make them happen.
An example would be like 1000 0001 being Move to TDSA.
This would take what is stored in an address in RAM and move it to a D-Latch called Temporary Data Storage A. 1000 0001 is all the "computer" sees, and it know that is has to move the data stored in the adress in RAM that something is being looked at to TDSA.
Our grade in the class is dependant on if our computer works. A if it does everthing it is supposed to, B if it is built and parts of it work, but 14 doesn't come out, C if it is built but doesn't work at all, D if it is parrtially built, and F if nothing gets done. The prof has informed us that there has been only a 25% success rate in the class. Only 25% of the people that take the class manage to get there computer computing. It is harder than it sounds, particularly if you aren't taking it at a school that has an EE major. Basically how we have been learning is he gave us the spec shets for the chips we are using, and then we had to figure out how to make the work for certain tasks, and now we have to put them all together into a device that has to work if we want an A.
But, it is a great class, it really makes you think about all the engineering that is involved in building the latest computers.
Think of thise, one NAND gate built on a breadbord with only transistors and diodes takes up the whole breadboard, but in a modern processor there are over a million NAND gates, and NAND gates are the simplest to build XOR, and OR gates are crazy.
Ok, I babble.
dhej
Re: An expanded version of what I said before
Don't you just love circuit design Dhej?
[SARCASM]I know I do.[/SARCASM] :p