Building a Turing Machine

10 Friday Dec 2021

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modeling, Python code, simulation, Turing Machine

I’m not sure how I got to thinking about Turing Machines (TMs). I was going through some files recently and spent some time looking at busy-beaver.c (from 2017 according to the file date). It contains an implementation of a TM. But something else got me speculating about my own implementation; I just don’t recall what.

I decided to actually write it when it occurred to me that I could use a Python generator to implement the Turing Machine tape. Sadly, I didn’t think of it in time for the trilogy I just published about Python generators (part 1, part 2, part 3).

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Full Adder Redux

14 Tuesday May 2019

Posted by Wyrd Smythe in CS101

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Tags

full adder, logic circuit, modeling, NOR gate, Python code, simulation, truth table

I’m returning to the full-adder logic circuit modeling to present the code for a version that tries to capture the timing of the signals.

The goal is to take a closer look at the intermediate states of the adder as signals trickle through it.

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Full Adder Sim V2.0

08 Wednesday May 2019

Posted by Wyrd Smythe in CS101

≈ 1 Comment

Tags

full adder, logic circuit, modeling, NOR gate, Python code, simulation, truth table

This is the third post in the Full Adder series. The first post explored ways to code the abstract model of a full-adder. The second post explored one way to code a simulation of a physical system (where the models are of the components of the system).

This post explores another gate-based model, but one with only one type of gate. This simulation is close to being transistor-level.

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Full Adder Simulation

07 Tuesday May 2019

Posted by Wyrd Smythe in CS101

≈ 1 Comment

Tags

full adder, logic circuit, modeling, Python code, simulation, truth table

In the last post, I explored different ways to model the logic of a full-adder. In this post I’ll explore a model of a physical instance of a full-adder — a model that simulates physical reality.

Because a full-adder is, at root, a mathematical expression, various software models can accomplish the same results. Models are abstractions, so the only thing a model can simulate perfectly is another model.

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