Breadboard computer

Introduction

As many others, I have wanted to build a breadboard computer from scratch since discovering Ben Eater’s excellent YouTube series on the subject.

After many years, I finally have gotten around to starting the build. My build will not be a one-to-one replication of Ben Eater’s build, I’ll attempt to make it my own. Some of the changes I plan to make:

• I’ll be using 74HCxx CMOS logic chips instead of 74LSxx TTL chips.
• Make sure to focus on signal and power integrity: Decoupling caps, don’t leave unused inputs floating, better power distribution.
• Incorporate improvements from breadboard computers from other people as they seem fit.
• Use 8 bit instructions instead of only 4 bits.

Posts

• Part 1 - Clock module - A clock module for the breadboard computer.

Software

Software used during the build

• Falstad circuit simulator (circuitjs) - Javascript circuit simulator, used for simulation and embedding of circuits in posts.
• Digital - Digital logic designer and circuit simulator

Resources and references

YouTube

Breadboard computers / CPUs

There are several YouTube channels with information about building breadboard computers. Among the channels I have found useful are the following:

• Ben Eater - Ben Eater’s channel, home of the project that initially inspired me to build my own breadboard computer.
• James Sharman - James Sharman is building a pipelined CPU from scratch. He has also made several input/ouput devices from scratch, like VGA, sound and UART.
• Fabian Schuiki - Fabian Schuiki is building a superscalar out-of-order CPU.
• DrMattRegan - Dr Matt Regan has several tutorials building different computers on breadboards.

General computer architecture

• Exploring how computers work - Playlist by Sebastian Lague exploring how computer works starting with logic gates, using his own Simulation tool.
• Computer architecture from scracth - Playlist by Core Dumped describing computer architecture starting with transistors.

Reddit

• /r/beneater - A subreddit dedicated to Ben Eater’s project and other projects based/inspired by them.

Other

• eater.net - Ben Eater’s site with information about his projects and project kits for sale.
• Digital Computer Electronics - This book by Albert Paul Malvino describes the SAP-1 computer (Simple-As-Possible 1), which forms the basis for Ben Eater’s computer.
  • Scanned version at the Internet Archive
• From Nand to Tetris - Course where you build a simulated computer from scracth.
  • Build a Modern Computer from First Principles: From Nand to Tetris - Coursera version of the course covering the first half of the book - Simulated hardware build
  • Build a Modern Computer from First Principles: Nand to Tetris Part II - Coursera version of the course covering the second half of the book - Software for the computer
  • The Elements of Computing Systems, second edition: Building a Modern Computer from First Principles - The course book at Amazon