Memory and Storage Devices Quiz

Memory

• Random Access Memory (RAM) is a memory scheme that stores data temporarily for prompt access by the processor.
• RAM is volatile, meaning data is erased when the power supply is turned off.
• Data is stored and accessed randomly in RAM.

ROM (Read Only Memory)

• A permanent form of storage that remains active regardless of power supply.
• Data stored on ROM devices cannot be modified.

Secondary Memory

• Stores data and programs permanently, even when power is turned off.
• Examples of secondary memory include:
  • Hard Disk (Disk drive or HDD): stores and provides quick access to large amounts of data on an electromagnetically charged surface.
  • Optical Disk: uses laser light to store data, with three main types: CD (up to 700MB), DVD (up to 8.4 GB), and Blu-ray disc (up to 50 GB).
  • Flash memory: a storage module made of flash memory chips, with no mechanical platters or access arms.

Output Unit

• An output device communicates the results of data processing to humans.
• Converts electronically generated information into human-readable form.
• Examples of output devices include:
  • Monitor
  • Printer: transfers data from a computer onto paper, with types including Laser, Ink Jet, and Dot Matrix.

Central Processing Unit (CPU)

• Also known as microprocessor or processor.
• Responsible for all functions and processes.
• Comprised of three main parts:
  • Arithmetic Logic Unit (ALU): executes arithmetic and logical operations.
  • Control Unit (CU): controls and coordinates computer components, reads code for the next instruction, and provides necessary data.
  • Registers: stores data to be executed next, with very fast storage area.

Software

• A generic term for organized collections of computer data and instructions.
• Broken into two major categories:
  • System software (Operating System): controls, integrates, and manages individual hardware components.
  • Application software: accomplishes specific tasks, such as image viewing, spreadsheet, or text processing.

Unit of Measurements

• Storage size examples:
  • 1 bit: answer to a yes/no question
  • 1 byte: a number from 0 to 255
  • 90 bytes: enough to store a typical line of text from a book
  • 4 KB: about one page of text
  • 120 KB: the text of a typical pocket book
  • 3 MB: a three-minute song (128k bitrate)
  • 650-900 MB: an CD-ROM
  • 1 GB: 114 minutes of uncompressed CD-quality audio at 1.4 Mbit/s
  • 8-16 GB: size of a normal flash drive

Computer Classification

• Computers can be classified by size and power into different categories.