ICT 0417 - Networks and the Effects of Using Them

Objective: Know and understand scanning the storage media used to transfer data.

1. Introduction to Data Transfer and Storage Media

Data transfer involves moving information from one location to another. This often requires storing the data on a storage medium before transfer. Different storage media have varying characteristics that affect transfer speed, capacity, and cost.

1.1 Common Storage Media

Several types of storage media are commonly used for data transfer:

• Hard Disk Drives (HDDs): Traditional storage using magnetic platters.
• Solid State Drives (SSDs): Uses flash memory for faster data access.
• USB Flash Drives (Thumb Drives): Portable flash memory devices.
• Memory Cards (SD, microSD): Used in digital cameras, mobile phones, and other devices.
• Optical Discs (CDs, DVDs, Blu-ray): Data is stored using lasers to read and write information.
• Network Attached Storage (NAS): Dedicated storage devices connected to a network.
• Cloud Storage: Data is stored on remote servers accessible via the internet.

2. Scanning Storage Media for Data Transfer

Scanning a storage medium refers to the process of reading data from it to prepare it for transfer. This involves several steps depending on the type of storage medium.

2.1 HDD Scanning

HDDs store data magnetically on spinning platters. Scanning an HDD involves:

1. Identifying the Disk:** The computer needs to identify the HDD through the BIOS or operating system.
2. Partitioning:** The disk is divided into logical sections called partitions.
3. File System:** The file system (e.g., NTFS, FAT32) organizes files and directories on the disk. The operating system reads the file system to locate files.
4. Reading Sectors:** Data is stored in sectors, which are the smallest units of storage on the disk. The HDD controller reads these sectors as the platters spin.
5. Data Transfer:** The read data is then transferred to the computer's memory.

2.2 SSD Scanning

SSDs use flash memory, which is electronically accessed. Scanning an SSD involves:

1. Identifying the Drive:** Similar to HDDs, the SSD needs to be identified by the operating system.
2. Mapping Logical Blocks:** SSDs are organized into logical blocks. The operating system uses a mapping table to locate these blocks.
3. Data Retrieval:** Data is retrieved by accessing the specific logical blocks.
4. Data Transfer:** The retrieved data is transferred to the computer's memory.

2.3 USB Flash Drive Scanning

USB flash drives also use flash memory. Scanning a USB drive involves:

1. Device Recognition:** The operating system recognizes the USB drive as a removable storage device.
2. File System Access:** The file system on the USB drive (usually FAT32 or exFAT) is accessed.
3. Data Reading:** The operating system reads the data from the flash memory chips.
4. Data Transfer:** The read data is transferred to the computer's memory.

2.4 Memory Card Scanning

Memory cards (SD, microSD) are similar to USB flash drives in terms of data storage and access. The scanning process is largely the same, involving:

1. Device Detection:** The operating system detects the memory card reader.
2. File System Access:** The file system on the memory card is accessed.
3. Data Reading:** Data is read from the flash memory.
4. Data Transfer:** The read data is transferred to the computer's memory.

2.5 Optical Disc Scanning

Optical discs store data as patterns of pits and lands on the disc surface. Scanning an optical disc involves:

1. Laser Reading:** A laser beam is shone onto the disc, and the reflected light is detected by a sensor.
2. Data Interpretation:** The patterns of light and dark are interpreted as binary data (0s and 1s).
3. Data Transfer:** The interpreted data is transferred to the computer's memory.

3. Effects of Using Different Storage Media

The choice of storage media significantly impacts data transfer speed, capacity, and other factors.

Storage Media	Transfer Speed	Storage Capacity	Portability	Cost
HDD	Slow	High	Low	Low
SSD	Fast	Medium to High	Medium	High
USB Flash Drive	Medium to Fast	Low to Medium	High	Medium
Memory Card	Medium	Low to Medium	High	Medium
Optical Disc	Slow	Medium	Medium	Low
NAS	High (network dependent)	High	Low (stationary)	High
Cloud Storage	High (internet dependent)	Scalable	High	Variable (subscription based)

The speed of data transfer is crucial for applications like video editing and gaming. Capacity determines the amount of data that can be stored. Portability is important for transferring data between different devices. Cost is a significant factor in choosing the appropriate storage media.

4. Conclusion

Understanding how data is scanned from different storage media is essential for effective data transfer. The choice of storage media depends on the specific requirements of the task, considering factors like speed, capacity, portability, and cost.