September 2018 – The Hacking Den

Introduction to Digital Computers 3: Flip Flops

It’s been about a month, and here’s the third video explaining how computers work from the ground up.

In this third video I discuss flip flops. Starting with two not gates hooked together I discuss how a bi-stable circuit operates, extend this using NOR gates to Set/Reset flip flops, build data flip flops, edge-triggered data flip flops and 8 bit registers which can store up to 8 digit base-two numbers. I also talk a little bit about signal delays through transistor circuits, setup and hold times, and I also briefly introduce edge-triggered Set/Reset flip flops, J/K flip flops and T flip flops, as well as how to use them to build a counter.

All of this, of course, literally comes from the ground up, since everything can be built using 2N3904 transistors, a few LEDs, 330&ohm; and 10k&ohm; resistors, and a few switches to wire it all up.

My hope is to release subsequent videos about once a month, give or take.

Gear Tooth Geometry.

I feel like, with making the first two “Introduction to Digital Computers” videos I’ve gained a superpower. And I’ve used that power to help me visualize and solve another problem I was having, figuring out the shape of spur gears (and eventually, internal spur gears, the next major feature I’d like to add to the Kythera application).

Which led me to making this video.

As always, show notes give further details.

Let me know if you find any problems or have any questions.

And as always, thanks for watching.