housekeeping

zk/Assembly.md

@@ -4,8 +4,6 @@ tags: [CPU]
 created: Tuesday, March 12, 2024
 ---
 
-# Assembly
-
 - Assembly is one level up from machine code and provides a more human-friendly
   abstraction layer
 
@@ -38,8 +36,3 @@ A disassembler does the opposite: translate machine code into assembly.
   directly executed by the CPU
 - humans use an assembly language version of the machine code which is then
   translated back to machine code for the computer to execute.
-
-## Related notes
-
-[[Hexadecimal_number_system]], [[Instruction_set_architectures]],
-[[CPU_architecture]]

zk/Attributes_of_Internet_enclosure.md

@@ -3,8 +3,6 @@ tags: [ecopolsoc, internet]
 created: Friday, November 22, 2024
 ---
 
-# a771a6d9_defining_internet_enclosure
-
 ## Defining _enclosure_
 
 The attempt by capital interests to encircle, control and contain networked

zk/Biconditional_Introduction.md

@@ -3,8 +3,6 @@ tags:
   - logic
 ---
 
-# Biconditional introduction
-
 The biconditional means if $P$ is the case, $Q$ must be the case and if $Q$ is
 the case, $P$ must be the case. Thus to introduce this operator we must
 demonstrate both that $Q$ follows from $P$ and that $P$ follows from $Q$. We do

zk/Bitwise_operators.md

@@ -4,8 +4,6 @@ tags: [binary]
 created: Saturday, April 20, 2024
 ---
 
-# Bitwise operators
-
 In addition to mathematical, logical and comparison operators, there are
 _bitwise operators_. These operators execute conditions based on the actual bits
 of a value rather than the values that the bits are encoded to represent.
@@ -68,5 +66,3 @@ operations are the fastest and lowest level of computation, being able to
 directly access and operate on bits within a programming language can be
 beneficial when efficiency and speed of execution is a factor or when memory is
 constrained.
-
-## Related notes

zk/Boolean_function_synthesis.md

@@ -5,21 +5,16 @@ tags:
   - logic
 ---
 
-# Boolean function synthesis
+When we looked at [boolean functions](Boolean_functions.md) we were working in a
-
+particular direction: from a function to a truth table. When we do Boolean
-When we looked at
+function synthesis we work in the opposite direction: from a truth table to a
-[boolean functions](Boolean_functions.md) we were
+function.
-working in a particular direction: from a function to a truth table. When we do
-Boolean function synthesis we work in the opposite direction: from a truth table
-to a function.
 
 This is an important skill that we will use when constructing
-[logic circuits](Digital_circuits.md).
+[logic circuits](Digital_circuits.md). We will go from truth conditions (i.e.
-We will go from truth conditions (i.e. what we want the circuit to do and when
+what we want the circuit to do and when we want it to do it) to a function
-we want it to do it) to a function expression which is then reduced to its
+expression which is then reduced to its simplest form and implemented with
-simplest form and implemented with
+[logic gates](Logic_gates.md). Specifically, NAND gates.
-[logic gates](Logic_gates.md).
-Specifically, NAND gates.
 
 We will show here that a complex logical expression can be reduced to an
 equivalent expression that uses only the NAND operator.
@@ -120,10 +115,8 @@ $$
 | 1   | 1   | 1          | 1                               |
 
 Finally, we can simplify even further by doing away with AND and NOT and using a
-single
+single [NAND gate](Logic_gates.md#nand-gate) which embodies the logic of both,
-[NAND gate](Logic_gates.md#nand-gate)
+being true in all instances where AND would be false: $\lnot (x \land  y)$.
-which embodies the logic of both, being true in all instances where AND would be
-false: $\lnot (x \land  y)$.
 
 Let's prove the theorem that every logical expression can be formulated as a
 NAND function. To do this we need to show that both NOT and AND can be converted

zk/Call_stack.md

@@ -31,7 +31,3 @@ console.log("Bye");
    function: the `console.log("bye")`
 6. Executes
 7. Returns to line that called it. Finds nothing else to do. Exits program.
-
-## Related notes
-
-![Stack memory](Stack_memory.md)

zk/Chipset_and_controllers.md

@@ -4,8 +4,6 @@ tags:
   - computer-architecture
 ---
 
-# Chipset and controllers
-
 A **controller** is simply a circuit that controls a process. The **chipset** is
 a combination of controllers placed on the same piece of silicon.
 

zk/Concise_subfield_mapping_JS.md

@@ -4,8 +4,6 @@ tags: []
 created: Friday, June 28, 2024
 ---
 
-# Concise mapping of object subfields in JS
-
 ## Scenario
 
 You have an array of objects and you want to return the objects with only a
@@ -33,5 +31,3 @@ More concise approach with destructuring:
 ```js
 const subset = arrayOfObjs.map(({ name }) => ({ name }));
 ```
-
-## Related notes

zk/Conditionals_in_Bash.md

@@ -3,8 +3,6 @@ tags:
   - shell
 ---
 
-# Conditionals in Bash
-
 ## If statements
 
 - Conditional blocks start with `if` and end with the inversion `fi` (this is a

zk/Creating_a_Linux_partition_table.md

@@ -146,7 +146,3 @@ sudo e2label /dev/sda1 my_human_name
 > Whilst we have created our partitions we cannot yet mount them. This is
 > because we have not yet set up a filesystem on the partitions. This is the
 > next step.
-
-## Related notes
-
-![Linux disk partitions](./Linux_disk_partitions.md)

zk/Current.md

@@ -2,8 +2,6 @@
 tags: [physics, electricity]
 ---
 
-# Current
-
 > Electrical current is the movement of electrons from negatively charged atoms
 > to positively charged atoms when an appropriate external force is applied.
 

zk/Delay_line_memory.md

@@ -3,8 +3,6 @@ tags: [computer-history, memory]
 created: Wednesday, September 18, 2024
 ---
 
-# Delay line memory
-
 - First described in the _First Draft_ by #vonNeumann based on work by Eckert
   and Mauchley.
 

zk/Delete_and_replace_characters_from_stdout_with_tr.md

@@ -4,8 +4,6 @@ tags:
   - procedural
 ---
 
-# Delete and replace characters from stdout with `tr`
-
 I used the following pattern to remove new lines and blank spaces:
 
 ```sh

zk/Docker_volumes.md

@@ -3,8 +3,6 @@ tags: [docker]
 created: Sunday, May 04, 2025
 ---
 
-# Docker volumes
-
 > This is a WIP re-write of [Docker Storage](./Docker_storage.md).
 
 ## _Bind mounts_ versus _named volumes_

zk/DynamoDB_CLI_commands.md

@@ -4,8 +4,6 @@ tags: [AWS, databases, dynamodb]
 created: Saturday, June 22, 2024
 ---
 
-# DynamoDB CLI commands
-
 ## Connecting to a local (Docker)/prod (AWS) DynamoDB instance
 
 In order to distinguish between local and production accounts you should keep
@@ -65,5 +63,3 @@ aws dynamodb scan \
 --table-name TimeEntries \
 --output table
 ```
-
-## Related notes

zk/DynamoDB_SDK_commands.md

@@ -4,8 +4,6 @@ tags: [AWS, databases, dynamodb]
 created: Sunday, June 23, 2024
 ---
 
-# DynamoDB SDK commands
-
 The following commands are for using `@aws-sdk/client-dynamodb` (the JS SDK).
 
 ## Create client
@@ -76,5 +74,3 @@ const params = {
 const dynamoDbDocumentClient = DynamoDBDocumentClient.from(client);
 const data = await dynamoDbDocumentClient.send(new ScanCommand(params));
 ```
-
-## Related notes

zk/DynamoDB_data_structure.md

@@ -7,8 +7,6 @@ tags:
 created: Sunday, June 09, 2024
 ---
 
-# DynamoDB
-
 ## Data structure
 
 ### Non-relational tables
@@ -129,5 +127,3 @@ I have also defined a GSI. This is derived from the `Year` attribute. This will
 group all the items by their `Year`, allowing me to query directly by year but
 also helping to chunk the entries which will make look-ups quicker and less
 expensive.
-
-## Related notes

zk/Expansions_and_substitutions.md

@@ -3,8 +3,6 @@ tags:
   - shell
 ---
 
-# Expansions and substitutions
-
 Bash is weird in that parentheses, braces and brackets are used not just as
 markers for different code blocks but as the designators of commands in their
 own right. The type of bracket you use effects how your input is interpreted.
@@ -79,10 +77,9 @@ the second list against them.
 ## Parameter expansion: `${...}`
 
 We use most frequently for returning the value of stored
-[variables](Variables_and_data_types_in_Bash.md).
+[variables](Variables_and_data_types_in_Bash.md). Techically we do not have to
-Techically we do not have to use the braces, we can retrieve with just `$var`
+use the braces, we can retrieve with just `$var` however it's better to use them
-however it's better to use them to minimise interpretation fuck-ups which happen
+to minimise interpretation fuck-ups which happen a lot.
-a lot.
 
 When the braces are used, this allows us to transform the values before they are
 returned such as only returning from the 6th character: `${var:6}`.
@@ -91,8 +88,7 @@ returned such as only returning from the 6th character: `${var:6}`.
 
 Command substitution (circle-brackets) allows us to put the output of one
 command inside another. Bash runs the bracketed command in a
-[sub-shell](Shell_sessions.md) and then returns it
+[sub-shell](Shell_sessions.md) and then returns it to the main user shell.
-to the main user shell.
 
 For example:
 
@@ -104,6 +100,4 @@ echo "The current directory is $(pwd)."
 
 We use arithmetic expansion when we want to calculate numerical values
 
-See
+See [Working with numbers in Bash](Working_with_numbers_in_Bash.md) for more.
-[Working with numbers in Bash](Working_with_numbers_in_Bash.md)
-for more.

zk/Firewalls.md

@@ -3,8 +3,6 @@ tags: [networks, servers, firewalls]
 created: Sunday, February 09, 2025
 ---
 
-# Firewalls
-
 A firewall is a server mechanism that filters incoming requests for resources
 and services that it hosts.
 

zk/Forgejo_runner_failure_after_VPS_reboot.md

@@ -3,8 +3,6 @@ tags: [docker, servers]
 created: Saturday, August 09, 2025
 ---
 
-# Forgejo runner failure after VPS reboot
-
 If you get stuck on "Waiting" when running an automated deployment in Forgejo,
 this can be because you've rebooted the VPS and the Docker permissions have
 reset.

zk/Git_rebasing.md

@@ -3,8 +3,6 @@ tags:
   - git
 ---
 
-# Rebasing
-
 Rebasing is a way to integrate changes from one branch into another. In this
 regarding it is like merging a branch B into another branch A. However rebasing
 differs from normal merging in the way in which it modifies the Git history.
@@ -127,11 +125,11 @@ request.
 ## Difference from cherry-picking
 
 The main difference between the two approaches is that
-[cherry-picking](Cherry_picking_a_branch.md) is a more selective
+[cherry-picking](/zk/Cherry_picking.md) is a more selective process, where you
-process, where you can pick and choose specific commits that you want to include
+can pick and choose specific commits that you want to include in another branch.
-in another branch. This can be useful when you only want to apply specific
+This can be useful when you only want to apply specific changes or fixes from
-changes or fixes from one branch to another, without including all the changes
+one branch to another, without including all the changes made in the original
-made in the original branch.
+branch.
 
 On the other hand, rebasing is a more comprehensive process that can include all
 the changes from one branch to another, but it modifies the commit history,

zk/Global_object_in_NodeJS.md

@@ -3,8 +3,6 @@ tags:
   - node-js
 ---
 
-# Global object
-
 > In Node every function and variable should be scoped to a module. We should
 > not define functions and variables within the global scope.
 

zk/Grep.md

@@ -3,8 +3,6 @@ tags:
   - shell
 ---
 
-# Grep
-
 ## Purpose of `grep`
 
 `grep` stands for “global regular expression print”. It allows you to search

zk/HTTPS.md

@@ -3,8 +3,6 @@ tags: [world-wide-web, internet, encryption, servers]
 created: Friday, December 14, 2024
 ---
 
-# HTTPS
-
 The problem with standard, unencrypted HTTP requests is that the data can be
 captured in transit and be observed or modified by malicious actors.
 
@@ -17,10 +15,10 @@ It utilises two types of encryption to send messages securely:
   - a single shared key between client and server to encrypt the messages sent
     between them
 - asymmetric encryption
-  - two keys are used: a [public key](./bbdcb54f_public_key_cryptography.md) to
+  - two keys are used: a [public key](/zk/Public_key_cryptography.md) to encrypt
-    encrypt the data and a private key to decrypt it. The public key can be
+    the data and a private key to decrypt it. The public key can be shared
-    shared freely so anyone can encrypt and send data to a peer but only the
+    freely so anyone can encrypt and send data to a peer but only the peer can
-    peer can receive and decrypt it
+    receive and decrypt it
 
 > Symmetric encryption applies once the server has been authenticated and its
 > public key has been shared with the client. Asymmetric encryption applies at

zk/Headless_Raspi_network_setup.md

@@ -8,8 +8,6 @@ tags:
 created: Wednesday, June 12, 2024
 ---
 
-# Headless network setup
-
 If you are using a headless system and you aren't using an ethernet connection,
 you face a chicken-egg issue of how to connect the device to WiFi via `ssh` when
 the device isn't yet on the network.
@@ -31,5 +29,3 @@ network={
      key_mgmt=WPA-PSK
 }
 ```
-
-## Related notes

zk/Heap_memory.md

@@ -4,10 +4,8 @@ tags: [memory, C]
 created: Saturday, April 20, 2024
 ---
 
-# Heap memory
+Along with [stack memory](/zk/Stack_memory.md), programs make use of _heap
-
+memory_ during runtime.
-Along with [[Stack_memory|Stack memory]], programs make use of _heap memory_
-during runtime.
 
 Heap memory does not use a standardised data structure and can be accessed from
 any point within the program.
@@ -36,5 +34,3 @@ The `malloc` method requests 512 bytes that it wants to assign to the `data`
 variable. It will return the address of the first byte in the newly allocated
 memory. `data` will then refer to the address on the stack that holds the
 address allocation on the heap.
-
-## Related notes

zk/Intro_to_the_Unix_shell.md

@@ -3,8 +3,6 @@ tags:
   - shell
 ---
 
-# Introduction to the Unix shell
-
 ## Unix based systems
 
 Many operating systems are based on the UNIX software architecture. macOS/OSX

zk/Invoking_the_shell_in_Python.md

@@ -4,8 +4,6 @@ tags: [python, shell]
 created: Monday, April 29, 2024
 ---
 
-# Invoking the shell in Python
-
 ```py
 import subprocess
 

zk/Key_figures_ARPANET.md

@@ -3,9 +3,7 @@ tags: [internet, ARPANET, ARPA]
 created: Monday, October 28, 2024
 ---
 
-# 4a3dc316_key_figures_ARPANET
+- [Paul Baran](/zk/Baran_distributed_networks.md) for his work at RAND on
-
-- [Paul Baran](385af4b4_Baran_distributed_networks.md) for his work at RAND on
   distributed networks as an alternative to the extant
   centralised/de-centralised phone networks.
 

zk/Lambda_programming_model.md

@@ -4,8 +4,6 @@ tags:
   - aws-lambda
 ---
 
-# AWS Lambda programming model
-
 The overall architecure consists in the following three processes:
 
 1. Triggers
@@ -18,8 +16,7 @@ See [AWS Lambda triggers](Lambda_triggers.md)
 
 ## Handler function
 
-See
+See [AWS Lambda handler function](Lambda_handler_function.md)
-[AWS Lambda handler function](Lambda_handler_function.md)
 
 ## Code
 

zk/Latches.md

@@ -7,7 +7,7 @@ tags: [logic-gates, binary, memory]
 The **combinatorial digital circuits** we have looked at so far have been
 non-sequential. The outcome is a function of its immediate set of inputs and
 everything happens at once: there is no means of storing state for future use.
-In other words there is no _[memory](Memory.md)_.
+In other words there is no memory.
 
 In contrast, the output of a **sequential digital circuit** depends not only on
 its present set of inputs but also on past inputs to the circuit. It has some
@@ -49,8 +49,7 @@ _The representation of an SR Latch in a digital circuit diagram_:
 
 The circuit diagram latch symbol obviously encapsulates more complex
 functionality that occurs at the sub-circuit level. We will demonstrate how this
-functionality can be achieved with two
+functionality can be achieved with two [NOR](Logic_gates.md#nor-gate) gates.
-[NOR](Logic_gates.md#nor-gate) gates.
 
 The two gates are in a **cross-coupled configuration**. This basically means
 that the wires are crossed back on themselves such that the output of one is

zk/Linux_disk_partitions.md

@@ -5,8 +5,6 @@ tags:
   - procedural
 ---
 
-# Linux disk partitions
-
 A disk is divided up into partitions which are subsections of the overall disk.
 The kernel presents each partition as a [block device](Devices.md#Devices) as it
 would with an entire disk.
@@ -96,8 +94,8 @@ The two tools disclose that the main harddrive is `/dev/nvme0n1` (equivalent to
 
 - The root partition is vital for the system's functionality. Without it, the
   system cannot boot or operate. It needs to be  
-   large enough to accommodate the operating system, installed programs, and system
+   large enough to accommodate the operating system, installed programs, and
-  libraries, but it doesn't need to store user data or  
+  system libraries, but it doesn't need to store user data or  
    additional applications, which can be located on other partitions.
 
 - This is the domain of the [superuser](User_Space.md#root-user-superuser). The
@@ -171,7 +169,3 @@ In our example above:
     </ul>
 </dd>
 </dl>
-
-## Related notes
-
-![Creating a Linux partition table](./Creating_a_Linux_partition_table.md)

zk/Listing_and_navigating_directories_in_the_Shell.md

@@ -3,8 +3,6 @@ tags:
   - shell
 ---
 
-# Listing and navigating directories in the shell
-
 ## Listing options
 
 Obviously we know that in order to list the files and sub-directories in our

zk/Logical_possibility_and_necessity.md

@@ -4,19 +4,17 @@ tags:
   - logic
 ---
 
-# Logical possibility and necessity
-
 ## Logical possibility
 
 In distinguishing the properties of
 [logical consistency](Logical_consistency.md) and
-[validity](Validity_and_entailment.md) we make tacit use
+[validity](Validity_and_entailment.md) we make tacit use of the notion of
-of the notion of **possibility**. This is because when we consider the validity
+**possibility**. This is because when we consider the validity of an argument we
-of an argument we are assessing truth-conditions and this consists in asking
+are assessing truth-conditions and this consists in asking ourselves what could
-ourselves what could or could not be the case: were it such that _P_, then it
+or could not be the case: were it such that _P_, then it would be the case that
-would be the case that _Q_. It is important to understand what possibility means
+_Q_. It is important to understand what possibility means in the context of
-in the context of logic and how it differs from what we might mean ordinarily
+logic and how it differs from what we might mean ordinarily when we use the
-when we use the term.
+term.
 
 It is evident from the case of arguments that are valid but not sound that logic
 operates with a specialised notion of possibility. For example it has to be the
@@ -60,9 +58,9 @@ From this we can derive the following property of logical possibility:
 A proposition is _logically necessary_ if it is true in every logically possible
 circumstance which is to say: true on every possible truth functional
 assignment. Necessity and
-[logical truth](Logical_truth_and_falsity.md#logical-truth)
+[logical truth](Logical_truth_and_falsity.md#logical-truth) are therefore
-are therefore synonyms: anything that is logically true (a tautology) is true by
+synonyms: anything that is logically true (a tautology) is true by necessity
-necessity (could not be otherwise.)
+(could not be otherwise.)
 
 Further, every logical truth is logically possible but not everything that is
 logically possible is logically true. It is possible that it is raining but this

zk/Magnetic_core_memory.md

@@ -3,8 +3,6 @@ tags: [computer-history, memory]
 created: Friday, September 27, 2024
 ---
 
-# Magnetic core memory
-
 ![](../img/magnetic-core-memory.jpg)
 
 Like [Magnetic_drum_memory](Magnetic_drum_memory.md), magnetic core memory was

zk/Monitoring_processes_and_resources.md

@@ -11,10 +11,9 @@ tags:
 
 ### `top`/`htop`
 
-We can use [ps](Processes.md) to list the
+We can use [ps](Processes.md) to list the currently running processes but it
-currently running processes but it does not provide much information about the
+does not provide much information about the resource metrics or how the process
-resource metrics or how the process changes over time. We can use `top` to get
+changes over time. We can use `top` to get more information.
-more information.
 
 `top` provides an interactive interface for the information that `ps` displays.
 It updates in real time and shows the most active processes based on the CPU
@@ -60,9 +59,8 @@ _Here I have pressed `u` to show only the processes associated with my user:_
     $ renice 20 1234
     ```
 - `VIRT`
-  - The total amount of
+  - The total amount of [virtual memory](/zk/VirtualMemory.md) used by the
-    [virtual memory](Virtual_memory_and_the_MMU_in_Linux.md) used by
+    process including: program code, data, shared libraries, pages that have
-    the process including: program code, data, shared libraries, pages that have
     been swapped, pages that have been mapped but not used.
 - `RES`
   - Stands for _resident size_
@@ -110,9 +108,8 @@ procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
     - Total amount of virtual memory in the
       [cache](Role_of_memory_in_computation.md#relation-between-cache-and-buffers)
 - `swap`
-  - Distinguishes amount of memory
+  - Distinguishes amount of memory [swapped](Swap_space.md) in (`si`) to memory
-    [swapped](Swap_space.md) in (`si`) to memory and
+    and swapped out (`so`) to disk
-    swapped out (`so`) to disk
 - `io`
   - Disk actions
   - Amount of data read from harddisk (`bi`)
@@ -136,8 +133,8 @@ gives me some useful info about which files VS Code is using:
 ## System calls: `strace`
 
 A system call is when a process requests a service from the
-[kernel](The_kernel.md), for instance an I/O operation to
+[kernel](The_kernel.md), for instance an I/O operation to memory. We can trace
-memory. We can trace these system calls with `strace`.
+these system calls with `strace`.
 
 ## CPU performance
 
@@ -168,8 +165,8 @@ $ uptime
 
 We know that processes primarily interact with virtual memory in the form of
 pages which are then translated to physical blocks by the kernel via the
-[MMU](Virtual_memory_and_the_MMU_in_Linux.md). There are several tools
+[MMU](Virtual_memory_and_the_MMU_in_Linux.md). There are several tools which
-which provide windows onto this process.
+provide windows onto this process.
 
 ### System page size
 

zk/Motherboard.md

@@ -8,12 +8,11 @@ tags:
 
 <img src="../img/motherboard-pi.jpg" width="400px"/>
 
+![](./img/motherboard-pi)
+
 The motherboard is the foundation of a computer. It allocates power and allows
-communication to and between the
+communication to and between the [CPU](CPU_architecture.md), memory,
-[CPU](CPU_architecture.md),
+[harddisk](What_are_disks.md) and all other hardware components.
-[RAM](Memory.md),
-[harddisk](What_are_disks.md) and all other hardware
-components.
 
 It is a printed circuit board and is always the largest board within the
 computer chassis.

zk/Processes.md

@@ -4,8 +4,6 @@ tags: [operating-systems]
 created: Friday, June 21, 2024
 ---
 
-# Processes
-
 Programs are sequences of machine instructions stored in a file. However they do
 not work by themselves. Something needs to load the file's intructions into
 memory, direct the CPU to run the program and manage it during runtime. The OS
@@ -46,11 +44,3 @@ therefore also a child (grandchild) of `terminator`.
 
 Each process has a unique identifier called a _process identifier_, a
 _processID_ or just _PID_.
-
-## Related notes
-
-![systemd](./systemd.md)
-
-![ps](./ps.md)
-
-![Monitoring processes and resources](Monitoring_processes_and_resources.md)

zk/Push_buttons.md

@@ -4,8 +4,6 @@ tags: [electronics]
 created: Tuesday, June 25, 2024
 ---
 
-# Push buttons
-
 Push buttons are push-to-make switches. This means that they are **on when they
 pressed and off when they are not pressed**. A classic example would be the
 switches on a keyboard.
@@ -30,7 +28,3 @@ _The push button being used as simple connector which does not break the
 circuit:_
 
 ![](../img/incorrect_push_button.jpg)
-
-## Related notes
-
-https://projects.raspberrypi.org/en/projects/button-switch-scratch-pi/1

zk/Querying_a_Mongo_collection.md

@@ -6,8 +6,6 @@ tags:
   - databases
 ---
 
-# Query a Mongo collection with Mongoose
-
 We now have the following entries in our `courses` collection:
 
 ```js
@@ -35,8 +33,8 @@ We now have the following entries in our `courses` collection:
 
 Now we will query the collection. This capability is provided via the Mongoose
 schema class we used to create the `Course`
-[model](Create_collections_and_documents_with_Mongoose.md#models).
+[model](Create_collections_and_documents_with_Mongoose.md#models). We have the
-We have the following methods available to use from the schema:
+following methods available to use from the schema:
 
 - `find`
 - `findById`

zk/ROM_versus_disk_loading.md

@@ -4,8 +4,6 @@ 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.
 
@@ -54,5 +52,3 @@ 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

zk/Role_of_unique_key_in_relational_databases.md

@@ -9,10 +9,9 @@ tags:
 > key is one **field that uniquely identifies each record**.
 
 This is essential for carrying out operations across database tables and for
-creating and deleting database entires in accordance with the
+creating and deleting database entires in accordance with the ACID principle. It
-[ACID principle](ACID_principle.md). It is also a safeguard: it means
+is also a safeguard: it means you can always identify a record by itself and
-you can always identify a record by itself and don't have to rely on generic
+don't have to rely on generic queries to identify it.
-queries to identify it.
 
 Sometimes you will have a dedicated field such as `UNIQUE_ID` for the unique
 key. Other times you can use an existing field to fulfil that function. When an

zk/SAM.md

@@ -9,7 +9,7 @@ AWS to simplify the process of building, deploying and managing serverless
 applications. It provides a concise syntax for defining the components of a
 serverless application, such as
 [Lambda functions](zk/Lambda_programming_model.md),
-[API gateway](/zk/AWS_API_Gateway.md) and database tables.
+[API gateway](/zk/API_Gateway.md) and database tables.
 
 The SAM infrastructure is defined in a YAML file which is then deployed to AWS.
 SAM syntax gets transformed into CloudFormation during the deployment process.
@@ -239,8 +239,8 @@ receive one file as an input. The packaging process consists in creating that
 single file.
 
 The packaging proces will first archive all of the project artefacts into a zip
-file and then upload that to [S3](zk/AWS_S3.md). A reference to this S3 entity
+file and then upload that to [S3](/zk/S3.md). A reference to this S3 entity is
-is then provided to CloudFormation.
+then provided to CloudFormation.
 
 ![](/img/s3-package-again.svg)
 

zk/Set_DNS_settings.md

@@ -4,8 +4,6 @@ tags: [Linux, networks]
 created: Wednesday, June 12, 2024
 ---
 
-# Set DNS settings
-
 ## Change the default DNS server
 
 On Arch and most modern Linux distributions domain name resolution is handled
@@ -62,8 +60,3 @@ nameserver 192.168.0.4
 nameserver fded:2060:8671:0:681:9bff:fe9b:37f0
 
 ```
-
-## Related notes
-
-![Network scanning](./Network_scanning.md)
-![Network debugging](Network_debugging.md)

zk/Signed_and_unsigned_numbers.md

@@ -3,17 +3,9 @@ tags:
   - binary
 ---
 
-# Signed and unsigned numbers
-
-## Summary
-
 - To represent negative integers in binary we use signed numbers._Signed binary_
   includes negative integers, _unsigned binary_ does not.
 
 - There are different methods of implementing the encoding of signed numbers.
   Two prominant approaches are **two's complement** and **signed magnitude
   representation**.
-
-## Related notes
-
-[[Twos_complement]], [[Binary_encoding]], [[Signed_magnitude_representation]]

zk/Signed_magnitude_representation.md

@@ -5,8 +5,6 @@ tags:
 created: Wednesday, March 20, 2024
 ---
 
-# Signed magnitude representation
-
 ## Summary
 
 ## Detail
@@ -25,13 +23,3 @@ the furthest bit (aka. the "most significant bit" (MSB)) at the $2^8$ position
 is `0`, designating that the number is unsigned. The signed equivalent is
 `1000 0101`, with the MSB being `1` designating the number as signed. When we
 are working with signed numbers, the MSB is known as the **signed bit**.
-
-### Advantages
-
-### Limitations
-
-## Applications
-
-## Related notes
-
-[[Signed_and_unsigned_numbers|signed_and_unsigned_numbers]]

zk/Single_file_Python_scripts.md

@@ -4,8 +4,6 @@ tags: []
 created: Friday, April 26, 2024
 ---
 
-# Single file Python scripts
-
 ## Basic architecture
 
 ```py
@@ -38,7 +36,3 @@ if __name__ == "__main__":
     main()
 
 ```
-
-## Related notes
-
-![Python modules and imports](./Python_modules_and_imports.md)

zk/Step_functions_and_state_machines.md

@@ -19,10 +19,8 @@ transitions between them. It also includes error catchers and retry logic.
 
 At the beginning you define a `StartAt` state which is the entrypoint of the
 state machine. This can be manually triggered, or more likely, triggered by
-another AWS service such as a
+another AWS service such as a [Lambda](Lambda_programming_model.md), an
-[Lambda](Lambda_programming_model.md), an
+[API Gateway](/zk/API_Gateway.md) request or a messaging/queue event.
-[API Gateway](AWS_API_Gateway.md) request or a messaging/queue
-event.
 
 The state machine ultimately ends at an end state. In between are various
 intermediary states which can include:

zk/Streams_in_NodeJS.md

@@ -5,14 +5,12 @@ tags:
 
 # Handling streams with fs
 
-When reading from a file, the
+When reading from a file, the [`fs.readFile()`](fs.md) method waits until the
-[`fs.readFile()`](fs.md) method waits
+entire file has been read before executing the callback. It's obvious why this
-until the entire file has been read before executing the callback. It's obvious
+might not be ideal in certain cases. If the file is very large you are utilising
-why this might not be ideal in certain cases. If the file is very large you are
+a lot of memory for a single process. Additionally, the data you need might
-utilising a lot of [memory](Memory.md) for a
+appear early in the file, in which case, once you find the data you want, there
-single process. Additionally, the data you need might appear early in the file,
+is no need to read to the end of the file.
-in which case, once you find the data you want, there is no need to read to the
-end of the file.
 
 > An example of this in practice is watching a Netflix film: we don't have to
 > wait for the whole film to download, we can start watching it immediately

zk/Syllogism.md

@@ -4,16 +4,14 @@ tags:
   - logic
 ---
 
-# Syllogism
-
 In order to make assertions about the relative
-[consistency](Logical_consistency.md) or inconsistency
+[consistency](Logical_consistency.md) or inconsistency of a set of propositions
-of a set of propositions we advance arguments. Consider everyday life: if we are
+we advance arguments. Consider everyday life: if we are having an argument with
-having an argument with someone, we believe that they are wrong. A more logical
+someone, we believe that they are wrong. A more logical way to say this is that
-way to say this is that we believe that their beliefs are inconsistent. In order
+we believe that their beliefs are inconsistent. In order to change their
-to change their viewpoint or point out why they are wrong we advance an argument
+viewpoint or point out why they are wrong we advance an argument intended to
-intended to show that belief A conflicts with belief B. Or if C is true, then
+show that belief A conflicts with belief B. Or if C is true, then you cannot
-you cannot believe that D.
+believe that D.
 
 In formal terms **an argument is a set of propositions comprising one or more
 premises and a conclusion. The conclusion is taken to be supported by the

zk/The_History_of_Computing_Swade.md

@@ -341,7 +341,6 @@ the ABC to make ENIAC.
   next problem
 
 - ISP removed the friction:
-
   - the instructions comprising the program would be prepared on tape or punched
     cards and read into electronic memory
   - the hardware configuration of the machine would remain the same accross
@@ -382,7 +381,7 @@ variety of different electronic methods for memory:
 
 - An experimental computer intended to create the
   [von Neumann architecture](CPU_architecture.md) using
-  [Williams_Tube_RAM](Williams_Tube_RAM.md)
+  [Williams_Tube_RAM](/zk/Williams_Tube_memory.md)
 
 - Developed at the Univesity of Manchester and completed in 1948.
 
@@ -407,7 +406,6 @@ variety of different electronic methods for memory:
   university departments who were expected to program it themselves. To this
   end, a formal programming paradigm was forged for the EDSAC which established
   the following:
-
   - subroutines as a library of common procedures available to programmers (e.g.
     printing a result, reading input tape, program checking, mathematical
     operations)

zk/Threads.md

@@ -4,8 +4,6 @@ tags: [operating-systems]
 created: Wednesday, June 26, 2024
 ---
 
-# Threads
-
 A ![process](Processes.md) is a running instance of a given program. A program
 runs sequentially handling one task at a time, however we may need to run
 certain tasks in parallel.
@@ -36,7 +34,3 @@ the number of cores that a device's CPU has deterimines how many threads can run
 at once. In practice, then, the CPU shuffles between multiple threads in
 [clock segments](Clock_signals.md). This is known as scheduling and is managed
 by the process that the thread belongs to.
-
-## Related notes
-
-![Processes](Processes.md)

zk/Trapdoor_functions.md

@@ -3,12 +3,10 @@ tags: [cryptography, encryption]
 created: Friday, December 20, 2024
 ---
 
-# a4601796_trapdoor_functions
+How does [public key cryptography](/zk/Public_key_cryptography.md) achieve the
-
+feat of making the encyrpted data only decipherable in one direction. In other
-How does [public key cryptography](./bbdcb54f_public_key_cryptography.md)
+words how come the same data can be encrypted with one key but only decryptable
-achieve the feat of making the encyrpted data only decipherable in one
+by another?
-direction. In other words how come the same data can be encrypted with one key
-but only decryptable by another?
 
 It is acheived by the use of **trapdoor functions**. These are functions that
 are easy to compute in one direction but extremely difficult to reverse. But

zk/Twos_complement.md

@@ -92,8 +92,3 @@ $$
   bit length of the system
 
 - Consequently two's complement can necessitate larger overall word lengths.
-
-## Related notes
-
-[[Signed_and_unsigned_numbers|signed_and_unsigned_numbers]],
-[[Binary_addition|binary addition]], [[Signed_magnitude_representation]]

zk/Usenet.md

@@ -17,8 +17,8 @@ and wanted a way to communicate with each other.
 
 ## Technology
 
-Usenet comprised a [distributed network](385af4b4_Baran_distributed_networks.md)
+Usenet comprised a [distributed network](/zk/Baran_distributed_networks.md) of
-of dedicated servers that exchanged messages over the **Network News Transfer
+dedicated servers that exchanged messages over the **Network News Transfer
 Protocol** (NNTP).
 
 A user would post a message to their local news server. The server would assign

zk/journald.md

@@ -5,8 +5,6 @@ tags:
   - procedural
 ---
 
-# `journald`
-
 `journald` is a program that comes as default with [systemd](systemd.md). It is
 a service for collecting and storing system-level log data. I keeps a track of
 all [kernel](The_kernel.md) processes. It is invaluable when tracing the source