2. Hard Drive (HDD): Device located in a computer tower/case that stores and retrieves program files and data files; also known as the C:drive. Computer Tower History of the HDD - Developed by IBM in order to create random access files; with high capacity and random access to data. - In 1956 it was commercialized; the IBM 305 RAMAC

3.  - Platter holds magnetic medium  - Magnetic recording material is layered onto aluminum or glass disc, the platter is then polished to a mirror-like surface  - Magnetic head on the actuator arm glides over the disk to read/write  - Controller electronics attached to the side control the read/write mechanism and the motor that provides the spin

4.  - Using the OS (Linux, Windows, Mac), the microprocessor (CPU) requests a file at the activation of a program  - Motherboard has everything connected and contains basic software; helps transfer command.  - That command is sent to the HDD, which finds the data, and simultaneously sends it to allow reading and writing of data.

5.  Information on the hard disk is in small magnetic domains; possible due to precision of platter and speed of medium  Data that is stored on the HDD is stored in files (strings of bytes), when a program running requests a file, the arm of the HDD retrieves those exact bytes and sends them to the CPU at the same time.  Electronics also assemble the magnetic domains into bytes for reading, and turn them back to domains for writing.

6.  Capacity: # of bytes a HDD contains, started with 5MB, can now be up to 4TB as of 2012.  - 1TB = 1000GB, 1GB = 1000MB, 1MB = 1000KB, etc  Data Rate: # of bytes/second to deliver to CPU, typically 5-40 MB/s.  Seek Time: Time between CPU’s request & send time, often 10-20 milliseconds.  Size of HDD is commonly 3.5 inches in desktops, and 2.5 inches in laptops.

7. New Features - Actuator head could land on a special area, External HDD using USB connection, Changes - Byte Capacity, weight, aesthetics, faster data rate and seek time, Goals - Surpass 5TB barrier (density), heat assisted magnetic recording ( HAMR ); enables different use of materials as the magnetic storage media, faster data rate and seek time, shrink in disk size, Areal density (AD) ; more bytes per inch without HDD destruction, idle usage (conservation).

8. Price as of 2013 - $1.3 per GB Leading Manufacturers/Products - Seagate, Toshiba, Western Digital - Churning Sound: As the arm of the HDD moves back and forth rapidly, it sets vibrations that our ears hear as sounds. - Similar to how a speaker works, which moves a lightweight cone back and forth hundreds of times per second to generate sound.

9.  Pcworld/com/article/127105/article.html  http://windows.microsoft.com/en-ca/windows/computer-parts#1TC=windows-7 http://windows.microsoft.com/en-ca/windows/computer-parts#1TC=windows-7  http://computer.howstuffworks.com/hard-disk.htm http://computer.howstuffworks.com/hard-disk.htm  http://electronics.howstuffworks.com/gadgets/audio-music/cassette.htm http://electronics.howstuffworks.com/gadgets/audio-music/cassette.htm  http://www.makeuseof.com/tag/technology-explained-how-does-a-hard-drive-work- nb/ http://www.makeuseof.com/tag/technology-explained-how-does-a-hard-drive-work- nb/  http://news.cnet.com/8301-17938_105-57577479-1/seagate-ships-4tb-desktop-hdd/ http://news.cnet.com/8301-17938_105-57577479-1/seagate-ships-4tb-desktop-hdd/  http://www.extremetech.com/computing/153879-storage-pricewatch-hdds-back-to- pre-flood-prices-ssds-grow-as-gb-holds-steady http://www.extremetech.com/computing/153879-storage-pricewatch-hdds-back-to- pre-flood-prices-ssds-grow-as-gb-holds-steady  http://www.computerweekly.com/feature/Hard-drive-capacity-emphasized-over- performancefor-future-enterprise-hard-drives http://www.computerweekly.com/feature/Hard-drive-capacity-emphasized-over- performancefor-future-enterprise-hard-drives  http://www.examiner.com/article/smr-hamr-tech-for-future-hdds http://www.examiner.com/article/smr-hamr-tech-for-future-hdds  http://wiki.answers.com/Q/What_part_of_the_computer_is_the_brain