LOGICS / Bench 03

Decoder Lab

A full decoder build, end to end.

A decoder takes n inputs and switches on exactly one of its 2ⁿ outputs. Decoder Lab walks a complete decoder build from start to finish: wire the decoder on the canvas, verify it behaves, then walk away with a materials list and a breadboard plan — before you've touched a single jumper wire.

Example · 2-to-4 decoder AA'BB' Y0Y1Y2Y3
Truth table
ABY0Y1Y2Y3
001000
010100
100010
110001
VerifiedExactly one output high for each input
How it works

Wire it, verify it, then build it.

01

Wire it

Build the decoder on the canvas: inputs, their complements, and one gate per output.

02

Verify it

Check the wiring against what a decoder must do — every input combination selects exactly one output — and catch mistakes on screen.

03

Get the materials list

The parts your verified design needs, counted for you, so the trip to the stockroom happens once.

04

Follow the breadboard plan

Where each chip sits and how the wires run, laid out before you build.

Before you build

Know the parts and the layout first.

For the 2-to-4 example above, this is the kind of plan you take to the lab bench. Your own lab sheet sets the final part list.

Materials list · example
74LS04 hex inverter2 of 6 inverters used
× 1
74LS08 quad 2-input AND4 of 4 gates used
× 1
Solderless breadboard× 1
+5 V supply× 1
Jumper wiresset
Breadboard plan · example U174LS04 U274LS08 +5 VGND
+5 V to pin 14 GND to pin 7 signal wires

Start building free.

Free

5 gates of your own on the canvas.

The built-in reference design doesn’t count toward it.

Pro

Unlimited gates.

See all plans →
Next bench · 04 Chip Bench →

Your design as actual 74-series ICs.

Open Decoder Lab