Lab46 Wiki

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<WRAP round fggray muchbigger box>HPC Fundamentals Course Notes wiki</WRAP>

======Login Problems======
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======Syntax======
For those unfamiliar, here is a page on [[wiki:syntax|wiki editing syntax]] that can be used here.

======Course Notes Wiki======
This is a space for members of the HPC Fundamentals class to create a source of information reflective and assisting to the course.

Aside from assignments that may have you specifically perform operations here, you should contribute when you encounter any of the following:

  * Some neat bit of information related to the class
  * Some clarification or understanding you've had with respect to concepts in the class
  * Organizational/style improvements to existing content
  * Questions you have that may deserve a more visual answer

====Computer Hardware Basics====

1. Power Supply
   * Receives power from the wall in AC form, then converts it to a more stable DC form which will not overload certain circuits. 
   * Sends power in various voltages to different parts of the computer through color-coated wires.{{ :notes:power_supply.jpg?nolink&400 |}}
2. Hard Drive
    * This is where we save data that we do not want to be lost. It has wires called "SATA" wires connected to it for data and power transfer.
    * It is usually solid and contains disks on which data is kept.{{ :lair:hard_disk_drive.jpg?nolink&400 |}}
3. RAM (Random Access Memory)
    * Temporary data storage
    * come in the forms of several smallish sticks. These hold a lot of data, but cannot store things when the power is removed from them.{{ :notes:ram.jpeg?nolink&400 |}}
4. Heat Sinks
    * Look similar to metal "combs" or a series of tall parallel planes. Their purpose is to prevent pieces from overheating, which can warp them and is bad for the computer in general.
    * These are Passively Cooling, there is also active cooling in the form of fans or water cooled systems.{{ :notes:heat_sink.jpg?nolink&400 |}}
5. Motherboard
    * Contains all the essential information on the computer
    * If you connect the pins in the pwd thing you can bypass security like some kinda hacker.{{ :notes:motherboard.jpg?nolink&400 |}}

====How to Search/Install/Uninstall in Debian====

    ***sudo apt-cache search "something"** :: This is useful for finding exactly the program package you want, such as **man-db, manpages, and manpages-dev**. Those will help you immensely with using things you know nothing about! 

    ***sudo apt-get install "something"** :: This is used to install the thing which you want.  It is case sensitive, so make sure to type the exact package you want.

    ***sudo apt-get update** :: Update everything you've installed, but do not push the updates to the software yet.  Also updates the apt-cache.

    ***sudo apt-get upgrade** :: Push the update to all software on your system.  Be careful, it may break your system if there is a bad bug in the new update!

    ***sudo apt-get remove --purge "something"** :: Will completely remove the program specified, including any "crumbs" leftover.

    ***sudo dpkg -l** :: This will display any programs/packages you currently have installed.  Useful to check what you have and don't have.

=====Raspberry Pi / Electronics=====

A useful beginner's guide on LEDs (especially how to calculate the ideal resistance):

  * https://www.instructables.com/id/LEDs-for-Beginners/

The Infrared LEDs we have (note the input voltage (1.5VDC) and amperage (50mA -> 0.05A)):

  * https://www.sparkfun.com/products/9349
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