PCB layout and 8-bit LED board.

Here is the full layout of my PCB which I cut up into smaller boards

Some of circuits I have not yet talked about as I have not yet built and tested them.

And one of the things I did not explained in my previous post (the Multiplexer) was the design of the 8-bit LED board.

So here is its schematic.

It consists of buffers which are made of two NOT gates after each other. And the resistor for the LED is also the Collector resistor for the proceeding BJT.