Watching Crash Course Computer Science? Build the circuits yourself
Crash Course Computer Science is a free video series from Crash Course, produced in collaboration with PBS Digital Studios and hosted by Carrie Anne Philbin. Its early episodes build a computer from the bottom up: electronic computing and the transistor (episode 2), Boolean logic and logic gates (3), binary numbers and letters (4), the ALU (5), registers and RAM (6), the CPU (7) and instructions and programs (8), before the series moves on to advanced CPU designs and programming. If an episode left you wanting to try the circuit yourself, digiwleea is a free, in-browser place to build it.
What Crash Course Computer Science is good at
It is a quick, friendly first look at how a computer works: each idea gets one short episode, with clear animations of gates, an ALU built from scratch, a latch matrix of memory and a CPU stepping through its clock cycles. (digiwleea is an independent project, not affiliated with Crash Course or PBS.)
Building the circuits yourself
Watching a circuit is not the same as wiring it and finding out why your first try does not work. In digiwleea you build the circuits from those episodes yourself, in the browser: the transistor as a switch, then gates, an adder and an ALU, latches, registers and RAM, and finally an 8-bit CPU that runs programs you write, in a guided 40+ level course with an AI tutor (Wleea). The simulator checks every part, and each part you finish is saved and reused in the next. Watch an episode for the big picture, then build its circuit here; the table below matches the hardware episodes to pages on this site.
| Crash Course Computer Science | digiwleea | |
|---|---|---|
| Format | Short animated videos | A live simulator and a course |
| You | Watch each circuit explained | Wire each circuit yourself, checked by the simulator |
| Goes from | Early computing to programming and beyond | The transistor to an 8-bit CPU you program |
| Price | Free | Free lab and Act I; Premium for the full course |
The hardware episodes, one by one
| Episode | Build or read it in digiwleea |
|---|---|
| 2. Electronic Computing | The transistor as a switch and the MOSFET simulator |
| 3. Boolean Logic and Logic Gates | NOT, AND and OR from transistors: NOT, AND, OR; or try every gate |
| 4. Representing Numbers and Letters with Binary | How binary works, text to binary, the ASCII table |
| 5. How Computers Calculate: the ALU | Half adder, full adder, ripple-carry adder, 4-bit ALU |
| 6. Registers and RAM | SR latch, gated D latch, register, the memory simulator |
| 7. The Central Processing Unit (CPU) | The fetch cycle and the CPU simulator |
| 8. Instructions and Programs | Machine code and assembly language |
Episode titles follow the list on thecrashcourse.com. For a longer, deeper path through the same ground, see the computer architecture courses compared.
No sign-up is needed to start: open the lab and place your first transistor, or read the free theory course. The account (and the AI tutor) are optional.
See for yourself: build a logic gate from transistors in the simulator, then follow the path from sand to an 8-bit CPU.
Open the digiwleea lab →Frequently asked
Can I build the circuits from Crash Course Computer Science?
Yes. digiwleea is a free in-browser logic simulator where you can wire the same circuits the hardware episodes show, from logic gates and an ALU to latches, RAM and a CPU, and test each one live, with nothing to install.
Which Crash Course Computer Science episodes are about hardware?
Episodes 2 to 9: Electronic Computing, Boolean Logic and Logic Gates, Representing Numbers and Letters with Binary, How Computers Calculate: the ALU, Registers and RAM, The Central Processing Unit, Instructions and Programs, and Advanced CPU Designs. From episode 10 the series turns to programming.
Is digiwleea free?
The sandbox lab and the first act of the course are free and need no sign-up. An optional account adds the AI tutor and cross-device sync; the full course and expanded AI tutoring are included in the monthly or annual Premium subscription.