First of all, thank you all for your willingness to help with this human-powered computer project!

Today I put in the mailbox 16 envelopes directed to you with what we can call the architecture of this [small] computer… The following attempts to explain you what it implies and what I would like you to do, besides waiting for the mail to arrive.


I designed a network of logic gates with a specific numerical function. A 4-bit binary number will enter into a network, and the network will output 1 or 0 depending if a property of the number is present or not.

The idea of this project is that each of you will perform the operation of a single logic gate, a component of this network. The “digital signals” will be transmitted through 1-bit postcards in the mailing system.

When the computer is running, you will receive either one or two postcards depending on your function, each of them containing one bit: either a 1 or a 0; this will be your input signal(s). Your function will tell you what is the corresponding output for the received input. You will write the output bit in your output postcard(s), and you will send it/them through the mailing system. The address for your output(s) and the stamp in the postcard will be ready already.

The architecture in this case consists in the logic gate that each of you has assigned, as well as in the pre-defined connections between all of you. As the architecture has been designed with a specific function, when all of us follow it and contribute with our small part, we will get to the expected result. A complex operation will be executed by simple interconnected steps.

The envelope

Each of you should receive soon the personalized envelope I sent you. The envelope should contain:

  • A card with your logic gate function: It says your name and the name of your function (NOT, AND, OR, BUFFER), it has a symbol, it contains the truth table, and it has a brief text explaining what should be your output depending on your input(s).
  • One, two or three output postcards: They have a stamp and the destination address written already. You will have plenty of space for writing your corresponding output bit, either 0 or 1.


As a participant of this project, what I would like you to do is the following:

  • Document in video (landscape mode) when any of these events happen – your face doesn’t have to appear, but it would be great if your voice could be there telling what is happening and the date and time:
    • You receive the envelope
    • You receive an input postcard
    • You receive another input postcard, if applies
    • You write the output bit in the output postcard(s)
    • You put the output postcard(s) in a mailbox
  • Make the previous events happen, i.e.
    • Receive the envelope and keep the contents in a safe place
    • Wait until you have the number of needed input postcards before writing your output bit in your output postcard(s) – depending on who you are, they may arrive with a delay between them of many days
    • Put the output postcard(s) in a mailbox :D
  • Send me your videos!

What’s next

I’m giving the architecture a “head start”. Tomorrow I will send the four postcards that represent a 4-bit binary number, so that this computer, powered by you, can start processing it.

When the computation ends, I want to gather all your videos and assemble some kind of explanation of what happened when “looking from above” – Something interesting about emergent complexity is that it arises even when the parts of a system (in this case all of you) are unaware of how they fit in the bigger picture.

If you have any questions at any point in time, let me know!

More info of what is this all about can be read here and here. And if you are wondering for which course this is, it’s for Project Development Studio.

Thank you very much!