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8-bit ALU (Arithmetic Logic Unit)

In this Instructable, I will be going through the process of building and understanding the architecture behind an ALU (Arithmetic Logic Unit). The ALU is part of a computer’s CPU (central processing unit) and it handles arithmetic and logic operations as the name suggests.

The ALU that we will be building is a far simpler version than what may exist on your computer. More complicated ALUs may handle 64-bit numbers and have many more functions than just addition and subtraction. The ALU that will be discussed here will only be able to perform addition and subtraction on 8-bit numbers and will be built from 74HC logic using XOR, AND, and OR gates. All of which will be explained in detail in this instructable.

- 26 AWG Multicore wire (4 meters)
- 4x 4-way DIP SPST switches
- 1x PTM Switch (through hole)
- 24x 470 Ohm resistors
- 24x 5V LEDs
- 5V Adapter
- 30 cm x 10 cm perf board
- 6x CD4070 (XOR gate)
- 4x LS7408 (AND gate)
- 4x LS7432 (OR gate)
- 5V Adapter

- Soldering Iron
- Solder
- Wire Cutter/Stripper
- Multimeter”

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