컴활 1,2급 필기::1과목 요약[균쌤]

Main Ideas & Concepts Covered

1) Computer Hardware Basics

Computer classification by processing power

• Supercomputers
• Mainframes
• Minicomputers
• Microcomputers

Minicomputer

• Includes hand-held devices such as smartphones
• Also refers to types of wearable computers

Digital vs. analog computers

• Digital computers
  • Use logic circuits
  • Similar behavior to electronic watches
  • Require calculations
  • Slow but accurate
• Analog computers
  • Use amplification circuits
  • Fast but not accurate
  • May not “produce a reaction” (subtitle phrasing)

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2) CPU Structure and Memory Behavior

CPU components

• Registers
  • Fastest; very small temporary storage inside the CPU
• ALU (Arithmetic Logic Unit)
  • Includes an adder
    • Addition / complement / accumulator behavior (as mentioned)
  • Includes a status register
    • Stores status information
• Control unit
  • Example: Program Counter (PC)
    • Stores the address of the next instruction to execute

RAM vs. ROM / BIOS / firmware

• RAM (main memory)
  • Volatile
  • Acts as a workbench
• ROM (called BIOS/firmware in subtitles)
  • Can be configured via CMOS
  • Purpose: supports self-diagnosis and system setup
  • Uses flash memory (subtitle wording)

ROM/BIOS responsibilities (as listed)

• Self-diagnosis
• Set the date
• Power management
• Boot order
• System password
• Default font
• Chipset information
• Plug and Play
• Hard disk type
• Antivirus settings

Secondary storage + storage technologies

• SSD
  • Smaller, lighter, faster than HDD
• Partitioning
  • “Divide storage”
• Formatting
  • Erase + initialize
• RAID
  • Striping: split/record one large dataset across multiple drives
  • Mirroring: record the same data across multiple disks
• Hard disk connection method
  • Mentions a stacking method using a serial approach

Cache vs. virtual memory (as described)

• Cache memory (“SM” in subtitles)
  • Bridges the speed gap between CPU and main memory
• Virtual memory
  • Described as secondary

Memory hierarchy (fastest → slowest)

• Registers (CPU)
• Cache
• Main memory (RAM)
• Secondary memory

Flash memory examples

• Used in MP3 players and digital cameras

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3) System Organization / Buses / I/O Coordination

Motherboard bus

• A “pathway” to transmit:
  • Data
  • Address control signals
  • etc.
• Includes:
  • Internal bus
  • External bus
  • Expansion bus

USB (subtitles’ key points)

• Can connect up to 127 devices
• Supports serial Plug-and-Play
• USB 3.0 color: blue

Plug-and-play

• Ability to set up hardware immediately without separate installation

Interrupts

• Compared to “emergency situations”
• Types:
  • External interrupts
  • Internal interrupts
  • Software interrupts

CPU speed/throughput coordination idea

• Mentions channels to resolve speed differences between CPU and I/O devices

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4) Units, Data Size Concepts, and Encoding

Bits and bytes

• 8 bits = 1 byte

Byte → larger units

• Subtitles mention:
  • 1024 (caption appears garbled; implied as 1 kilobyte)
  • Then:
    • Megabytes
    • Gigabytes
    • Terabytes
    • Petabytes

Speed unit prefixes (slowest upward)

• micro, nano, pico, femto, attosecond
• A memory trick was suggested (subtitle garbling)

Component/grouping sequence (as stated)

• bits → bytes → words → fields → records → files → databases

Character encodings (bit sizes per subtitles)

• BCD: 6 bits
• ASCII: 7 bits
• EBCDIC: 10 bits
• Unicode: 16 bits

System purpose (4 goals)

• Reduce response time
• Improve processing power
• Enhance reliability
• Improve usability

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5) Software Categories and System Software

Operating system

• Described as system software

Control programs vs. processing programs

• Control programs
  • Monitoring
  • Task management
  • Data management (subtitle links this to monitoring/task management)
• Processing programs
  • Service problem handling
  • Language translation programs
  • Administrative tasks

Software types

• “Player” mentioned as free of charge
• Open-source software
  • Includes source code
  • Free use for a limited period (subtitle wording)
• Beta versions
  • Test versions used by the general public
• Commercial software
  • Sold for money

Utilities

• Said to be not essential elements for computer operation

Processing modes

• General processing: process tasks “all at once”
• Real-time processing: process tasks immediately
• Multi-programming: multiple programs simultaneously
• Time-sharing: divide time to use the system

Multi/dual core & parallelism (subtitle terms)

• Mentions:
  • “Dual-core processors include multiprocessing and duplexing”
• Multiprocessing
  • Multiple CPUs to improve computation
• Duplexing
  • Multiple CPUs prepared for failures

Distributed processing

• Works over a network
• Suitable for server-client models

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6) CPU Generations & Windows/GUI Multitasking Concepts

By circuit generation (as narrated)

• 1st generation: vacuum tubes
• 2nd: transistors
• 3rd: direct current (subtitle wording)
• 4th: LSI
• 5th: VLSI

Windows GUI multitasking

• GUI-based (image-based)
• Supports preemption-free multitasking (as stated)
• Task termination shortcut mentioned: Ctrl+Shift+Esc
• Multitasking meaning: handle multiple tasks simultaneously

Object Linking and Embedding (OLE) / mis-captioned

• Function described as “Object Linking Include”
• Can link/include objects (images/sounds) even across different programs

File system

• Mentions NTFS as superior to FAT
• Subtitle includes confusion about volume size (“not 256 terabytes”)

Windows shortcuts (mostly garbled but enumerated)

• F1: Help
• F2: Rename
• F3: Search
• (Likely) F5: Refresh
• F: Full Screen
• Ctrl+Esc: Start menu
• Ctrl+A: Select all
• Ctrl+Z: Undo
• Ctrl+W: Close tab
• Ctrl+D-style and other Windows shortcuts were mentioned (many captions garbled), including:
  • Windows Key + D: Desktop
  • Windows Key + Arrow Keys: tiling/move (as described)

Display / resolution

• Configure multiple displays
• Resolution = horizontal pixels × vertical pixels

Personalization

• Set background, lock screen, etc.

Taskbar features (Windows)

• Start button, Search, taskbar area, “Show task” buttons
• Notification area
• “Show desktop” equivalent to Win+D
• Toggle/Search/visibility controls
• Position and resizing, auto-hide, lock, jump lists, small icons

Accessibility Center

• Features:
  • Narrator
  • High Contrast
  • Magnifier
    • On/off: Win + and Win -
    • Close: Win+Esc
• Keyboard:
  • On-Screen Keyboard, Sticky Keys, Toggle Keys (and other garbled mentions)
• Mouse:
  • “Mouse Keys” to move via keypad
• Settings mentioned:
  • Left/right hand, click speed, pointer speed, text display position
  • Keyboard input time, repeat speed, blinking speed

Fonts

• Mentions:
  • TTF
  • Other variants (garbled)
• Add fonts via Control Panel Fonts or the Windows Fonts folder

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7) Windows Control Panel / Utilities / System Tools

Backup and Restore

• Can restore updates and system files
• Personal files cannot be restored (as stated in subtitle)

Accounts

• Administrator
  • Can do most tasks
• Standard
  • Cannot perform system-affecting actions

System Information

• Windows version, processor info, RAM, computer name, workgroup, activation status

Device Manager

• Lists hardware
• “?” indicates a driver not installed
• Subtitle described a drive as software holding hardware information (wording garbled)

Internet Options

• Set homepage
• Delete items (subtitle garbled)
• History compared to pages
• Cookies store information like IDs/passwords

Folder properties

• Access via a garbled shortcut
• Set:
  • read-only
  • hidden
  • sharing

Devices and Printers

• Configure printer settings
• Local printers need connection via a port
• Default printer: only one

Spool memory

• Temporary storage for parallel processing
• Called spool memory
• Located in secondary storage

Print quality unit

• DPI = dots per inch

Explorer options

• Folder Options
  • General tab: protect personal info (and other garbled text)
  • View tab: how files are displayed
  • Search tab: search-related responsibility settings (garbled)

Programs feature

• Uninstall/modify programs
• Delete updates
• Turn Windows features on/off

Task Manager / preemption

• Mentions terminating running programs via shortcut (caption garbled)
• Mentions “preemption”

Registry

• Database storing hardware/software info
• Run via: regedit

Disk Cleanup

• Free space by removing unnecessary files
• Also performs error checking

Error checking

• Checks physical and logical errors

Optimization / Defragmentation

• Removes fragmentation scatter to improve speed

Recycle Bin behavior

• Configurable per drive
• If full: deletes older files first
• Subtitle says files inside cannot be executed or copied
• Permanent deletion scenarios include:
  • Deleted externally (USB/network)
  • Deleted using DOS Elite command (garbled; likely a del/shift-delete variant)
  • Deleted using Shift key
  • When changing Recycle Bin properties

File extension & associated program

• File extension: 3–4 characters after the dot
• Associated program: program linked to the file
• Notepad notes:
  • Doesn’t support inserting images (garbled detail)
  • Supports TXT
• Shortcut/icons:
  • Icons have .LNK extension
  • Deleting a shortcut doesn’t delete the original file

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8) Multimedia Concepts and File Formats

Multimedia characteristics

• Integration, large capacity, interactivity, digital nature, non-linearity

Graphics concepts

• Dithering: generate new colors from suggested colors
• Modeling: create 3D graphics
• Rendering: display reality using shadows and colors
• Anti-aliasing: smooth jagged/pixelated edges
• Morphing: smooth transitions
• Interlacing: gradually becoming more distinct

Reality technology acronyms

• VR: Virtual Reality
• AR: Augmented Reality

Publishing / streaming / e-learning / community acronyms

• DTP: electronic publishing / computer-based book creation
• VOD: Video on Demand
• CAI: computer-aided education (and medical methods) using desktop multimedia
• DMB: terminals (service to watch broadcasts, per subtitle)
• ABS: location-based service
• VCS: video conferencing system
• Kiosk: unmanned system
• Telematics: vehicle information and communication

Image data

• Bitmap vs. vector
  • Bitmap: pixel-based → jagged edges when enlarged
  • Vector: lines/curves → no jagged edges when enlarged

Compression / formats mentioned

• J-Pack (bitmap-based)
  • Lossy and lossless compression support
  • Good compression ratio → smaller tile sizes
• F-files (meaning unclear/garbled)
  • Moving images; supports up to ~250 pixels
  • Transparent background colors
• PNG
  • Good compression
  • Supports transparent background colors

Audio data

• Sampling rate
  • Number of samples per second (subtitle garbled as “headcount”)
• File examples:
  • WAV, MP3 players, AIMP FF (sampling methods, subtitle wording)
  • Music-score-style electronic transfer mentioned (garbled)

Video data

• Streaming
  • Play while downloading
• Examples: ASF, WMV, RAM
• Codec
  • Converts analog ↔ digital video signals

Video standards / “M-pack” system (as stated)

• “M-pack” concept: codecs with appended numbers
• Examples listed:
  • M-pack: video/quality around 12
  • M2: HD TV or DVD
  • MP4: primarily used in video transmission
  • MP7: facilitating video retrieval
  • M-2NE1: standard for distributing/managing these M-packs

Information transmission methods

• Unidirectional
  • One direction only (TV/radio)
• “Duplicate” (subtitle garbled)
  • One side transmits while the other handles many requests
• Full-duplex
  • Simultaneous sending and receiving (like a telephone)

Network types / topologies (subtitle mapping)

• Centralized (star-shaped)
  • One central node connected to others one-to-one
• Bus type
  • Limited line resources; described as “low/limited”
• Distributed (hierarchical/tree-shaped)
• Network type & complete type
  • All computers connected to each other
• Peer-to-peer (P2P)
  • File sharing among individuals

Network scale terms

• LAN, ICN, BGM described as different communication scales

ISDN

• Comprehensive digital data communication network

Value-added networks (VAN / VAT in subtitle)

• Intranet: internal company network
• Extranet: extension of intranet
• Wireless LAN (WLAN)

Communication equipment

• Port: connects computers
• Repeater: amplifies digital signals
• Bridge: connects two communication networks
• Router: chooses optimal path
• Gateway: connects different networks
• Modem: digital ↔ analog conversion

Protocols & packet basics

• Protocols
  • Communication standards
  • Functions: flow control, synchronization, error control
• Packets
  • Data transport units
• TCP
  • Bundles info with addresses, divides into packets, flow control, error checking
• IP
  • Interprets addresses, routes packets, sends to host
• FTP
  • File transfer protocol; cannot execute files on FTP server (as stated)
• Email protocols (as listed):
  • POP3: receiving
  • SMTP: sending
  • MIM: used for mapping (subtitle garbled)
  • EMA: multimedia email-related protocol
• HTTP
  • Hypertext transmission protocol
• Remote control protocol (subtitle mentions “Teleson”)

IP addressing

• IP address
  • Internet access address for a computer
• DHCP
  • Automatically assigns IP addresses
• Manual settings require:
  • IP address
  • subnet mask
  • gateway
  • DMS (likely DNS, subtitle garbled)
• IP format
  • Decimal dotted notation: 32 bits (subtitle first said “four bits,” then corrected to 32)
  • Classes A–E: Class A for large-scale
• IPv6-like concept mentioned:
  • Hex, 128 bits
  • Unicast / anycast / multicast

DNS and domains

• Domains/URLs are internet addresses
• “NS lookup” mentioned (subtitle ends mid-sentence)