Category: 8-bit Computer

8-bit computer Starting to take shape

Posted on by Phillip Jubb
my 8-bit computer on its base board

Time to get moving on my 8-bit computer project….

Decided to to start combining the modules and setup the final configuration. This involved removing the protective backing from the mounting tape on the breadboards and committing to their final position on the computer.

I’m still short a few breadboards, and still waiting on quite a few components that are on the slow boat from China, but i wanted to get it a bit more organised and complete the modules I can.

Did just find that the clock module is on a breadboard that is ever so slightly different in size than the newer boards, so I may have to remake it if I can’t get passed the OCD about those 2mm.

I also did some checking with a multi-meter and found that the power distribution will need to be beefed up to make sure that all of the breadboards have the required 5v as there seems to be a significant drop as you move away from the clock module. Thanks to Paul at South West Makers for the advice. I’ll be putting it into practise shortly.

Check out all my 8-bit computer posts.

The Clock Module

Posted on by Phillip Jubb

The clock module synchronises the working inside the CPU. It triggers changes in state and timing of most if not all of the computer.

The clock module consists of 3x 555 Timer IC’s which are used to generate a timing pulse and also to de-bounce input from the user when taking single steps or changing the clock from run to step.

The variable resistor allows for variable clock speeds. The second and third 555 timers debounces the step input and the step/run select switch. Denouncing removes the tendency for the switch/button to “double tap” itself when the user triggers it. This happens in a fraction of a second which humans can’t see but computers are just that fast.

8-bit Computer

Posted on by Phillip Jubb

When I did my qualifications in computing in the 90’s, one of the basics I feel I missed out on was how computers work at an electronics level.

Recently I have been watching as series of videos on youtube by Ben Eater. This video series explains how a computer works on a fundamental level. Ben builds an 8-bit computer on breadboards.

This project is my investigations based on his work and is an attempt to make myself more aware of the underlying hardware I use everyday actually works..

Check out Ben’s videos on his Youtube Channel

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