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Digital logic

4-bit CPU from logic gates

Advanced120 min

Build a simple processor from transistors and gates, to see what is really inside a chip.

What you get

A 4-bit CPU executing instructions step by step, with visible registers, adder and clock.

Parts (simulated)

  • Built-in logic lab
  • Transistors and gates
  • Clock and logic probes

Nothing to buy: every component here is simulated in the browser.

Project steps

  1. 01Build the basic gates from transistors.
  2. 02Assemble a flip-flop, then a 4-bit register.
  3. 03Build a full adder in cascade.
  4. 04Add the clock and the instruction sequencer.
  5. 05Run a small program step by step.

What you learn

  • From transistor to logic gate
  • Storage with flip-flops
  • Binary addition
  • Instruction cycle

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