CALCULATOR PROJECT HELP????

Digital Logic Design PROJECT

(do this project with circuit maker design (7485 comparator))

Design 8 bit adder/subtractor (a+b, or a-b) with following:
specifications:
1. Inputs: tow operands [A,B](8-bit each),
operation(0-addition,1-subtraction),
load(1-load new data,0-perform operation).

2. Outputs: 9 - bit (8-bit will be stored in A again).

3. Modes of operations:

a. Check if B is 0, then the output will be A.
b. Check if A is 0, then the output will be B OR B' depend
on the operation.
c. Otherwise , perform the addition or subtraction.

4. Display result on two seven segment displays + 1 LED.

please if u know the answer help me and i will be thankfull.

I didn't get it: what r ur restrictions? Using logic gates? U can't use PIC or microprocessors?

There exists the 74181 ALU to do it and also incorporates many more functions.

Project restrictions...

I still dunno what r luizza's restrictions...