diff --git a/.obsidian/workspace.json b/.obsidian/workspace.json index d7868d8..7a66b82 100644 --- a/.obsidian/workspace.json +++ b/.obsidian/workspace.json @@ -21,7 +21,7 @@ "state": { "type": "markdown", "state": { - "file": "Semester 2/Programming 2/Week 2/Week 2 Programming 2.md", + "file": "Semester 2/Computer Systems Internals & Linux/Week 1/Week 2 Computer Systems Internals.md", "mode": "source", "source": false } @@ -95,7 +95,7 @@ "state": { "type": "backlink", "state": { - "file": "Semester 2/Programming 2/Week 2/Week 2 Programming 2.md", + "file": "Semester 2/Computer Systems Internals & Linux/Week 1/Week 2 Computer Systems Internals.md", "collapseAll": false, "extraContext": false, "sortOrder": "alphabetical", @@ -112,7 +112,7 @@ "state": { "type": "outgoing-link", "state": { - "file": "Semester 2/Programming 2/Week 2/Week 2 Programming 2.md", + "file": "Semester 2/Computer Systems Internals & Linux/Week 1/Week 2 Computer Systems Internals.md", "linksCollapsed": false, "unlinkedCollapsed": true } @@ -135,7 +135,7 @@ "state": { "type": "outline", "state": { - "file": "Semester 2/Programming 2/Week 2/Week 2 Programming 2.md" + "file": "Semester 2/Computer Systems Internals & Linux/Week 1/Week 2 Computer Systems Internals.md" } } }, @@ -177,8 +177,9 @@ }, "active": "13f4c5e19c9ab3c8", "lastOpenFiles": [ - "Semester 2/Programming 2/Week 1/Week 1 Programming 2.md", "Semester 2/Programming 2/Week 2/Week 2 Programming 2.md", + "Semester 2/Computer Systems Internals & Linux/Week 1/Week 2 Computer Systems Internals.md", + "Semester 2/Programming 2/Week 1/Week 1 Programming 2.md", "Semester 2/Programming 2/README.md", "Semester 2/HCI/README.md", "Semester 2/Database Systems/README.md", @@ -222,7 +223,6 @@ "Semester 1/Database Systems/Assignment/Populating Database.md", "Semester 1/Database Systems/Assignment/postgre Compatible.md", "images/Pasted image 20231204191255.png", - "Semester 1/Database Systems/Assignment/Creating Tables.md", "Database Systems/Untitled.canvas", "Untitled 1.canvas", "Untitled.canvas" diff --git a/Semester 2/Computer Systems Internals & Linux/Week 1/Week 2 Computer Systems Internals.md b/Semester 2/Computer Systems Internals & Linux/Week 1/Week 2 Computer Systems Internals.md new file mode 100644 index 0000000..760f245 --- /dev/null +++ b/Semester 2/Computer Systems Internals & Linux/Week 1/Week 2 Computer Systems Internals.md @@ -0,0 +1,40 @@ +# Clock Drift + +Recalibrate clocks when out of sync: + +- Async Transmission + - Send a small amount of data, then 1, then 0, then some more data. +- Manchester Encoding + - Send each bit as 2 values + - Original 10MBase-T uses this +- HDB3 encoding + - 3 logic levels to ensure no static sequences + - Used for long distance cables +- 4B5B encoding + - Transmit 5 bits of signalling to represent 4 bits of data + - 100MBase-T uses this. + +# Quantities in Digital Communication + +## Bit + +- Short for "binary digit". Byte = 8 bits + +## Data Rate + +- Bits per second + +## Baud Rate + +- Times per second the transmitted signal changes. + +### Examples + +- A modem used for dialup will encode at least six bits of data for each unit of signalling. +- Ethernet uses between 1.2 and 2 units of signalling per bit of data. + +# Text Encoding Communication + +- The word "Up" -> ASCII is 85, 112 +- Binary stream -> 010101010110000 +This demonstrates the worst case scenario for 4B5B, and 4 zeros to demonstrate HDB3.