Autosave: 2024-10-18 20:00:02
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37 changed files with 139 additions and 107 deletions
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@ -3,6 +3,8 @@ tags:
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- theorems
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---
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# Additive inverse property
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**Let $a$ represent any member of $\mathbb{Z}$. Then there is a unique member of
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$\mathbb{Z}$ $-a$ such that:**
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@ -2,6 +2,8 @@
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tags: [algebra]
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---
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# Algebra key terms
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- **Variable**
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- A symbol that stands for a value which may vary
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- **Equation**
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@ -4,6 +4,8 @@ tags:
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- theorems
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---
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# Axioms of set theory
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The basic notions of set theory are defined in
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[Basic properties of sets](Basic%20properties%20of%20sets.md). There we
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introduced a formal syntax that will be utilised to define the axioms. For easy
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@ -3,6 +3,8 @@ tags:
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- set-theory
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---
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# Basic properties of sets
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## Set theory
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Set theory is a sub-discipline of both mathematics and formal logic. In
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@ -4,6 +4,8 @@ tags:
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- logic
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---
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# Conjunction Introduction
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If two conjuncts have each been independently derived then they can be
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conjoined. Also known more simply as _Conjunction_
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@ -1,11 +1,12 @@
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---
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id: h7f8
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tags:
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- disks
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- Linux
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created: Monday, May 06, 2024
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---
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# Creating a Linux partition table
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## Creating a partition table
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To demonstrate the process of partitioning a harddrive I am going to repartition
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@ -3,7 +3,7 @@ tags: [memory, hardware]
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created: Friday, July 12, 2024
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---
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# DRAM_and_SRAM_memory
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# DRAM and SRAM memory
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There are two types of RAM memory: [SRAM and DRAM](./DRAM_and_SRAM_memory.md).
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@ -6,7 +6,7 @@ tags:
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created: Saturday, March 30, 2024
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---
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# Docker_CLI
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# Docker CLI
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```sh
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# List images
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@ -3,6 +3,8 @@ tags:
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- shell
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---
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# Environmental and shell variables
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## Important!
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To understand the difference between environmental and shell variables know
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@ -43,8 +45,7 @@ spawned instances? Is this even possible or do they die on `exit` .
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- The environment is an area that the shell builds every time that it starts a
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session. It contains variables that define system properties.
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- Every time a
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[shell session](Shell-sessions-e6dd743dec1d4fe3b1ee672c8f9731f6)
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- Every time a [shell session](Shell-sessions-e6dd743dec1d4fe3b1ee672c8f9731f6)
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spawns, a process takes place to gather and compile information that should be
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available to the shell process and its child processes. It obtains the data
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for these settings from a variety of different files and settings on the
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tags: [algebra]
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---
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## Equivalent equations
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# Equivalent equations
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> Two equations are equivalent if they have the same
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> [solution](Algebra%20key%20terms.md#678811) set.
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### Demonstration with addition
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$$ x - 4 = 3
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$$
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x - 4 = 3
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$$
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The [solution](Algebra%20key%20terms.md#678811) to this equation is $7$
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$$ x -
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4 (+4) = 3 (+ 4) $$
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$$
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x -
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4 (+4) = 3 (+ 4)
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$$
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Here we have added $4$ to each side of the equation. If $x = 7$ then:
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### Demonstration with subtraction
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$$ x + 4 = 9
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$$
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x + 4 = 9
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$$
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The [solution](Algebra%20key%20terms.md#678811) to this equation is $5$.
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$$ x +
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4 (-4) = 9(-4) $$
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$$
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x +
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4 (-4) = 9(-4)
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$$
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Here we have subtracted $4$ from each side of the equation. If $x = 5$ then:
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### Demonstration with multiplication
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$$x \cdot 2 = 10 $$
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The [solution](Algebra%20key%20terms.md#678811) to this equation is $5$.
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$$x \cdot 2 = 10 $$ The [solution](Algebra%20key%20terms.md#678811) to this
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equation is $5$.
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$$
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(x \cdot 2) \cdot 3 = 10 \cdot 3 $$ Here we have multiplied each side of the
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equation by $3$. If $x =5$ then
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$$\frac{x
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\cdot 3}{3} = \frac{18}{3}
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$$
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Here we have divided each side of the equation by $3$. If $x$ is 6, then
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$$\frac{6
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\cdot 3}{3} = 6$$
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$$
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\frac{6
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\cdot 3}{3} = 6
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$$
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$$\frac{18}{3} = 6 $$
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- fractions
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---
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# Equivalent fractions
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Two fractions are equivalent if they represent the same value. To begin with we
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can represent this visually:
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- fractions
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---
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# Expressing whole numbers as fractions
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Being asked to express a natural number as a fraction seems confusing at first
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but you need to just know that for any whole number $n$, you express it as a
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fraction with $\frac{n}{1}$.
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- prealgebra
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---
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## Factors and divisors
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# Factors and divisors
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The terms **factor** and **divisor** are used interchangeably. They are
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different ways of expressing the same mathematical truth and this is because of
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- prealgebra
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---
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# Formal conventions
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## Grouping symbols
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We use parentheses to delimit the part of an expression we want evaluated first.
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We only write one equals sign per line. For example, if we are resolving
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parentheses:
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$$ \begin{equation} \begin{split} 2 + \[3 + (4+5)\] = 2 + \[3 +9\] \\ = 2 + 12
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\\ = 14 \end{split} \end{equation} $$
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$$
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\begin{equation} \begin{split} 2 + \[3 + (4+5)\] = 2 + \[3 +9\] \\ = 2 + 12
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\\ = 14 \end{split} \end{equation}
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$$
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We call parentheses (`()`), brackets (`[]`) and braces `{}`) grouping symbols.
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When groupings (say parentheses) are used, the expression inside any pair of
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- theorems
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---
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# Fundamental Theorem of Arithmetic
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> Every integer greater than one is either a prime number itself or is product
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> of a unique combination of primes.
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- REST
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---
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# HTTP request types
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## GET
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- Get data
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- fractions
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---
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# Increasing fractions to their highest terms
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Given the equivalence between factors and divisors we can increase fractions to
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higher terms in a very similar way to when we reduce fractions. In the latter
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case we are dividing by divisors to reduce. In the former, we are multiplying by
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- shell
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---
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# Introduction to the Unix shell
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## Unix based systems
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Many operating systems are based on the UNIX software architecture. macOS/OSX
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- prealgebra
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---
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# Inversion of operators
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## Addition, subtraction
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Addition is the inverse of subtraction: $$(x - a) + a = x$$ $$ (6 - 2) + 2 = 6
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$$
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Subtraction is the inverse of addition: $$(x + a) - a = x$$ $$ (3 + 2) - 2 = 3$$
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Division is the inverse of multiplication $$ \frac{a \cdot x}{a} = x$$
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$$ \frac{6
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\cdot 3}{6} = 3$$
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\cdot 3}{6} = 3
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$$
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Multiplication is the inverse of division $$ a \cdot \frac{x}{a} = x$$
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$$ 2 \cdot
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\frac{8}{2} = 8$$
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$$
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2 \cdot
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\frac{8}{2} = 8
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$$
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@ -4,7 +4,7 @@ tags: [python, shell]
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created: Monday, April 29, 2024
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---
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# Invoking the shell_in_Python
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# Invoking the shell in Python
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```py
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import subprocess
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- procedural
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---
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# Killing processes
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## Kill a process running on a port
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For example a local server.
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|
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@ -3,6 +3,8 @@ tags:
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- shell
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---
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# Listing and navigating directories in the shell
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## Listing options
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Obviously we know that in order to list the files and sub-directories in our
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|
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@ -3,7 +3,7 @@ tags: [computer-history, memory]
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created: Friday, September 27, 2024
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---
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# Magnetic_core_memory
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# Magnetic core memory
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|
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@ -3,7 +3,7 @@ tags: [computer-history]
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created: Friday, September 27, 2024
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---
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# Mainframe_computers
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# Mainframe computers
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A mainframe computer, also known as a "big iron" is a high performance computer
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used for resource-intensive tasks that require greater security and availability
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|
|
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@ -3,7 +3,7 @@ tags: ["question"]
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created: Thursday, August 01, 2024
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---
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# Memory_versus_processor
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# Memory versus processor
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> Would a more powerful processor with average or reduced memory capacity
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> perform better than, equal to, or less than a less powerful processor with
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|
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- node-js
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---
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# Module wrapping at runtime in NodeJS
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## The Module Wrapper Function
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When Node runs each of our module files are wrapped within an
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|
|
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@ -3,6 +3,8 @@ tags:
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- prealgebra
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---
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# Natural numbers
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## The set of natural numbers
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$$ \mathbb{N} = {1, 2, 3, ...} $$
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|
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tags: [algebra, exponents]
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---
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# Negative exponents
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When calculating the exponents of a negative number the answer will always will
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be positive:
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|
|
|
@ -3,7 +3,7 @@ tags: [networks, hardware]
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created: Tuesday, August 06, 2024
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||||
---
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# Network_card
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# Network card
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The network card (technically know as the Network Interface Card (NIC)) or
|
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_network adapter_ is the hardware device that allows a computer to connect to a
|
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|
|
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@ -3,7 +3,7 @@ tags: [networks]
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created: Saturday, August 03, 2024
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---
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# Network_hosts
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# Network hosts
|
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|
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A network **host** or **node** is a single computing device attached to a
|
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|
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@ -1,10 +1,9 @@
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|||
---
|
||||
id: 5043
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tags: [node-js]
|
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created: Friday, April 26, 2024
|
||||
---
|
||||
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# NodeJS_scripts
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# NodeJS scripts
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||||
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If we want to use NodeJS as a scripting language without going to the trouble of
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setting up an NPM-based development environment, we can use the following
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|
|
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@ -3,6 +3,8 @@ tags:
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- prealgebra
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---
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# Order of operations
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1. Evaluate expressions in **parentheses**
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1. Evaluate **exponents**
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1. Evaluate **multiplications and divisions** from left to right in the order
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|
|
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@ -4,7 +4,7 @@ tags:
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- number-theory
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---
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### Prime factorisation
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# Prime factorisation
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Prime factorisation is the activity of expressing a composite number as the
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unique product of [prime numbers](Primes%20and%20composites.md). There are two
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> $n$. We then repeat this process with the resulting factors working
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> recursively until the numbers we are left with are primes.
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_The prime factors of 27 are 2, 3, 3_
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 _The
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prime factors of 27 are 2, 3, 3_
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it doesn't matter which products we choose as the interim factors, we should
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always reach the same outcome:
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|
|
|
@ -4,7 +4,7 @@ tags:
|
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- number-theory
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---
|
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## Prime and composite numbers
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# Prime and composite numbers
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|
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Definition of a **prime number**:
|
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|
|
|
@ -1,58 +0,0 @@
|
|||
---
|
||||
id: rmvm
|
||||
tags: [computer-architecture, memory]
|
||||
created: Monday, June 24, 2024
|
||||
---
|
||||
|
||||
# ROM versus disk loading
|
||||
|
||||
I will explore the concept via the practical examples of cartridge-based and
|
||||
disk-based video games console.
|
||||
|
||||
When you insert a disk into an Xbox, the game data is typically read from the
|
||||
disk and transferred into the console's memory by the OS. If the game is
|
||||
installed to the hard drive, this initially involves transferring substantial
|
||||
amounts of data to speed up future access. When you insert a cartridge into a
|
||||
console like the SNES, the data is not transferred in the same way. Instead, the
|
||||
cartridge contains a ROM chip that, when inserted, integrates directly with the
|
||||
motherboard. From the operating system’s point of view, this ROM chip behaves as
|
||||
an extension of the system’s memory architecture.
|
||||
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||||
The primary advantage of a ROM-based game is significantly reduced latency. The
|
||||
game data can be accessed as rapidly as any other data moving along the buses of
|
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the motherboard. With a disk, the data must first be read into a buffer and then
|
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transferred to a memory address where it can be accessed by the CPU.
|
||||
|
||||
With a ROM, while the console CPU still uses its own RAM to run the game
|
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(similar to disk-based systems), the game data on the ROM can be loaded into
|
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this RAM more quickly because it is directly attached to the motherboard. This
|
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makes the ROM cartridge effectively a fast, directly connected storage device.
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However, despite its speed, the limitation of a ROM cartridge is its storage
|
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capacity—it can hold only as much data as the chip can accommodate. In contrast,
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a disk can store much more data. This larger storage capacity allows not just
|
||||
for bigger and more complex games but also for the possibility of expanding the
|
||||
game through additional data downloaded to the console's hard drive. Such
|
||||
expansions or patches represent additional data from the console’s storage that,
|
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combined with the original disk data, are synthesized in memory at runtime for
|
||||
enhanced or updated gameplay experiences.
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||||
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||||
(Note however that modern cartridge-based consoles like the Nintendo Switch can
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also combine ROM-data with expanded data from the console HDD, sourced from the
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internet.)
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Both disks and ROMs are forms of static storage in the context of a game
|
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console. While disks can technically be overwritten with new data, in practice,
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manufacturers implement various locks and protections to prevent this. Any
|
||||
changes or additions to the game, such as patches or expansions, are not written
|
||||
back to the original disk. Instead, these updates are stored on the console's
|
||||
hard drive.
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||||
|
||||
Therefore, if you download an expansion for a game on your Xbox, the original
|
||||
disk remains unchanged as when you first purchased it. Consequently, if you were
|
||||
to take that disk and load it on another Xbox, it would not include any of the
|
||||
expansions or updates. The game would function in its original form, as the
|
||||
additional content and updates reside solely on the hard drive of the first
|
||||
console where they were downloaded.
|
||||
|
||||
## Related notes
|
|
@ -9,22 +9,50 @@ created: Monday, June 24, 2024
|
|||
I will explore the concept via the practical examples of cartridge-based and
|
||||
disk-based video games console.
|
||||
|
||||
When you insert a disk into an XBox, the game data is transferred from the disk
|
||||
into the console's memory by the OS. When you insert a cartridge into a SNES,
|
||||
there is no transferral of data. The game data is stored on a chip and this chip
|
||||
is attached to the motherboard. From the point of view of the OS, it is just
|
||||
another chip along with the others that comprise the motherboard.
|
||||
When you insert a disk into an Xbox, the game data is typically read from the
|
||||
disk and transferred into the console's memory by the OS. If the game is
|
||||
installed to the hard drive, this initially involves transferring substantial
|
||||
amounts of data to speed up future access. When you insert a cartridge into a
|
||||
console like the SNES, the data is not transferred in the same way. Instead, the
|
||||
cartridge contains a ROM chip that, when inserted, integrates directly with the
|
||||
motherboard. From the operating system’s point of view, this ROM chip behaves as
|
||||
an extension of the system’s memory architecture.
|
||||
|
||||
The chief advantage with a ROM game is that the latency is greatly reduced. The
|
||||
game data can be accessed as rapidly as any other data travelling along the
|
||||
busses of the motherboard. With a disk, the bytes have to be transferred in a
|
||||
buffer from the disk into a memory address and from there, accessed by the CPU.
|
||||
The primary advantage of a ROM-based game is significantly reduced latency. The
|
||||
game data can be accessed as rapidly as any other data moving along the buses of
|
||||
the motherboard. With a disk, the data must first be read into a buffer and then
|
||||
transferred to a memory address where it can be accessed by the CPU.
|
||||
|
||||
With a ROM, the console CPU still uses its own memory to run the game (as with
|
||||
disk-based consoles), it is just that the game data on the ROM can be loaded
|
||||
into memory quicker because it is attached to the motherboard.
|
||||
With a ROM, while the console CPU still uses its own RAM to run the game
|
||||
(similar to disk-based systems), the game data on the ROM can be loaded into
|
||||
this RAM more quickly because it is directly attached to the motherboard. This
|
||||
makes the ROM cartridge effectively a fast, directly connected storage device.
|
||||
|
||||
becomes part of the motherboard just like the other chips that comprise the
|
||||
motherboard.
|
||||
However, despite its speed, the limitation of a ROM cartridge is its storage
|
||||
capacity—it can hold only as much data as the chip can accommodate. In contrast,
|
||||
a disk can store much more data. This larger storage capacity allows not just
|
||||
for bigger and more complex games but also for the possibility of expanding the
|
||||
game through additional data downloaded to the console's hard drive. Such
|
||||
expansions or patches represent additional data from the console’s storage that,
|
||||
combined with the original disk data, are synthesized in memory at runtime for
|
||||
enhanced or updated gameplay experiences.
|
||||
|
||||
(Note however that modern cartridge-based consoles like the Nintendo Switch can
|
||||
also combine ROM-data with expanded data from the console HDD, sourced from the
|
||||
internet.)
|
||||
|
||||
Both disks and ROMs are forms of static storage in the context of a game
|
||||
console. While disks can technically be overwritten with new data, in practice,
|
||||
manufacturers implement various locks and protections to prevent this. Any
|
||||
changes or additions to the game, such as patches or expansions, are not written
|
||||
back to the original disk. Instead, these updates are stored on the console's
|
||||
hard drive.
|
||||
|
||||
Therefore, if you download an expansion for a game on your Xbox, the original
|
||||
disk remains unchanged as when you first purchased it. Consequently, if you were
|
||||
to take that disk and load it on another Xbox, it would not include any of the
|
||||
expansions or updates. The game would function in its original form, as the
|
||||
additional content and updates reside solely on the hard drive of the first
|
||||
console where they were downloaded.
|
||||
|
||||
## Related notes
|
||||
|
|
|
@ -4,7 +4,7 @@ tags:
|
|||
- fractions
|
||||
---
|
||||
|
||||
## Reducing fractions to their lowest terms
|
||||
# Reducing fractions to their lowest terms
|
||||
|
||||
> A fraction is said to be _reduced to its lowest terms_ if the
|
||||
> [greatest common divisor](Factors%20and%20divisors.md#greatest-common-divisor)
|
||||
|
|
Loading…
Add table
Reference in a new issue