To start off Day 3, I worked on the ALU (Arithmetic Logic Unit) of the CPU, which will perform addition and subtraction. I built the 8-bit adder/subtractor using 8-bit inputs for the first number to be added/subtracted: A0-A7 and the second number: B0-B7. Then, I used 2 full adder ICs and connected them in a ripple form, so that the C_out of the first one is the C_in to the second.
Then, I wired the logic that I implemented earlier, and tested a few combinations such as (5+3 = 8, 5-3=2, and etc.)
Here is the Lapse for Day 3 Part 1: https://lapse.hackclub.com/timelapse/HgUVg1cJHHOm