logicshell - logic circuits created using C and bash
What is logicshell?
Logicshell is a project that grew out of a conversation on logic circuits with a friend. It all started when we wondered if it would be possible to simulate a simple logic circuit using operating system tools only.
How can we build this?
First, we must view the most fundamental features of our logic circuit: electrons and current. Suppose the null-byte is an electron. Then, /dev/zero provides an infinite supply of electrons and /dev/null a supply of holes (virtual positively charged particles). Let's call these devices Vss and Vdd, respectively.
In our project we use a unix pipe as a wire, that is, a conductor with parasitic capacitance. If the wire is connected to Vss, its pipe buffer in kernel space quickly fills up with null-bytes, and the wire acts like a negatively charged metal plate. If it is connected to Vdd, the pipe buffer is drained, and the wire acts like a positively charged metal plate.
Because of the directionality of the pipes, where you write in a tip and read in the other, we can consider that the wire will always be equivalent to a diode, allowing the passage of the logic signal in one direction only.
Wires may thus carry logic signals: A wire that is filled with null-bytes corresponds to a logic zero, and a wire that is completely empty corresponds to a logic one. A wire that contains some null-bytes, but is neither full nor empty, corresponds to an undefined voltage, and will act as a logic one or a logic zero depending upon how we measure it.
Transistors
Coming soon.
Resistors
Coming soon too.