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The 4 to 16 line / instruction decoder

A project log for The Cardboard Computer

My goal is a 4-bit cpu using discrete transistors. I am learning from scratch as I have never worked with hardware at the gate level.

Mark Nesselhaus 12/22/2016 at 02:001 Comment

After the adder was finished, I then decided to keep on going and the instruction decoder was next on my hit list. Not much in the number of images except for the final result. the left and bottom edges are the input buffers and inverters using npn transistors. The rest are AND gates using only diodes. This is the last build using thumb tacks on a wood base.

The close wiring on the decoder was a real headache but like the ALU, it worked without errors. ( well, one wrong transistor got mixed in )

Discussions

Yann Guidon / YGDES wrote 12/22/2016 at 22:07 point

Some people say I'm crazy.
I'll show them your work :-D

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