Chapter 2 – Hardware: Computer & Mobile Devices

Objectives Overview

• Identify and briefly describe the functions of the primary components of a computer.

• Give examples of recent innovations in:

  • Processor chips

  • Memory devices

  • Input/Output devices

• Recognize characteristics and typical usage of single-user vs. multi-user computer systems.

• Identify and classify today’s mobile devices.

Why Learn About Hardware?

• Proper hardware choices can:

  • Improve productivity

  • Increase revenue

  • Reduce costs

  • Provide better customer service

• Managers are expected to understand hardware in order to:

  • Define business needs accurately

  • Ask informed questions when purchasing equipment

  • Evaluate competing options and total cost of ownership

• Hardware is any machinery (most of which uses digital circuits) that assists in input, processing, storage, and output within an information system.

• Decision criteria: How well does the hardware support the information-system objectives and the broader goals of the organization?

Fundamental I-P-O Cycle (Keyboard → CPU → Monitor Example)

• 1. Input:

  • User presses the letter “A”.

  • Keyboard sends scan code through the data bus to CPU.

• 2. Processing:

  • CPU interprets the keycode.

  • If necessary, fetches additional instructions/data from RAM via:

  • Address bus (locate)

  • Data bus (transfer)

• 3. Output:

  • CPU sends the character “A” back through data bus to the monitor for display.

• Buses in action:

  • Address bus → “where” in memory

  • Data bus → “what” data values travel in/out of devices or RAM

Inside the Case

• Core components visible in desktops & laptops:

  • Motherboard (main circuit board)

  • CPU (often under a heat sink & fan)

  • Memory modules (DIMMs or SODIMMs)

  • Video card & sound card (may be integrated or discrete)

  • Power-supply unit (PSU) or laptop battery

  • Ports, connectors & supporting circuitry

  • Cooling components (fans, heat sinks, liquid-cooling pipes on high-end rigs)

Motherboard & Computer Chips

• Motherboard = backbone that interconnects CPU, RAM, expansion slots, chipset, buses, and I/O ports.

• Computer chip = small slice of semiconducting material containing integrated circuits (ICs).

Processor (CPU)

• Interprets and carries out basic instructions.

• Contains two primary sub-components:

  • Control Unit (CU): directs operations, fetch-decode-execute cycle.

  • Arithmetic Logic Unit (ALU): arithmetic, logic, comparison.

• Multi-core processor: single chip with $\ge 2$ independent cores, enabling true parallelism.

• Machine Cycle (repeats per instruction):

  1. Fetch

  2. Decode

  3. Execute

  4. Store

• Registers: ultra-fast storage locations inside the CPU for immediate data/instruction use.

• System clock synchronizes all operations. Clock speed measured in gigahertz (GHz), e.g., $3.2\,\text{GHz} = 3.2 \times10^{9}\,\text{cycles/sec}$.

• Leading PC-class CPU vendors: Intel, AMD.

• Heat production → need for thermal solutions: heat sinks, fans, liquid cooling, cooling pads for laptops.

Cloud Computing (Hardware Perspective)

• Servers in remote data-centers supply storage, processing & apps via Internet.

• Benefits:

  • Accessibility (anywhere, any device)

  • Cost & space savings (pay-as-you-go, no on-site server rooms)

  • Scalability (rapid up/down provisioning)

Data Representation

• Analog signal: continuous, varying magnitude.

• Digital signal: discrete ${0,1}$ states (on/off electric charge).

• Binary system: only two digits → bit.

  • $1\,\text{byte} = 8\,\text{bits}$

• ASCII example (capital “T”):

  • Keyboard scan code → ASCII $01010100$ stored in RAM → displayed as character.

Memory Fundamentals

• Stores instructions, data in use, and results.

• Each memory cell has a unique address.

• Capacities typically expressed in gigabytes (GB) or terabytes (TB).

• Volatility:

  • Volatile (e.g., RAM) → contents vanish without power.

  • Non-volatile (ROM, flash, CMOS) → contents persist.

• RAM life-cycle example (loading OS, launching browser, opening paint app, closing app) demonstrates dynamic loading/unloading.

Types of RAM

• DRAM family (needs refresh):

  • SDRAM → DDR → DDR2 → DDR3 → DDR4 (each generation doubles or improves transfer rate)

  • RDRAM (Rambus) for niche high-speed uses.

• SRAM: faster, costlier, used for cache.

• Form factors: SIMM, DIMM, SODIMM.

Cache Hierarchy

• L1 (inside core, fastest, smallest)

• L2 (inside or on package, larger)

• L3 (shared among cores, on motherboard or package)

• Purpose: keep frequently used instructions/data closer to the CPU → reduce average access time.

ROM & Firmware

• Read-Only Memory stores permanent instructions (e.g., BIOS/UEFI firmware).

Flash & CMOS

• Flash memory: electrically erasable, rewritable; basis for SSDs, USB drives.

• CMOS: low-power tech used for configuration settings memory.

Access Time Metric

• Measured in nanoseconds $(1\,\text{ns} = 10^{-9}\,\text{s})$; lower = faster.

Adapters & Expansion

• Adapter card enhances/extends system (graphics, sound, networking).

• Expansion slot: receptacle on motherboard (PCIe, PCI, etc.).

• Plug-and-Play (PnP): OS automatically recognizes and configures hardware.

• Mobile equivalents: USB adapters, ExpressCard modules, other removable flash-based adapters.

System Buses

• Bus = shared pathway for data/addresses between components.

• Main categories:

  • System (front-side) bus: CPU ↔ memory/controller hub.

  • Backside bus: CPU ↔ L2 cache.

  • Expansion bus: CPU/memory ↔ peripheral cards (e.g., PCIe, USB).

• Word size: number of bits CPU can process at once; common desktop value $64\,\text{bits}$.

Power Supply & Battery

• PSU or AC adapter converts $AC \rightarrow DC$ power.

• Mobile devices run from PSU or rechargeable lithium-ion batteries.

Protecting Hardware

• Physical: cable locks.

• Electrical issues:

  • Undervoltage (brownout, blackout)

  • Overvoltage (surge)

• Protection devices:

  • Surge protector (suppresses spikes)

  • Uninterruptible Power Supply (UPS) = surge protection + battery backup.

Desktop & Mobile Computers

• Personal Computer (PC): stand-alone system for single user.

• Desktop: stationary, components fit on/under desk.

• Laptop/Notebook: folding clamshell; screen in lid, keyboard in base; portable.

• Tablet: thin, touch-centric slate or convertible models.

• Handheld computer: fits in one hand.

Mobile Devices

• Smartphone: Internet-capable phone with OS, apps, multi-input (touch screen, mini-keyboard, slide-out keyboard, virtual/swipe keyboards).

• Internal design: “System on a Chip” integrating CPU cores, RAM, ROM, modem, I/O controllers, power regulation.

• Digital camera: CCD captures light → analog signal → ADC converts to digital → processor adjusts quality → stored on flash media.

• Portable media player: stores/plays audio, video.

• E-book reader: optimized for reading digital texts (e-ink or LCD).

• Game devices:

  • Home/portable consoles, handheld units.

  • Controllers: gamepads, joysticks, wheels, dance pads, motion-sensing wands, guitars, balance boards.

Embedded Computers

• Dedicated, special-purpose computer within a larger product.

• Domains: consumer electronics, home automation, automobiles, industrial robots, office machines.

• Automotive examples: telematics, adaptive cruise control, tire-pressure sensors, airbag deployment logic, electronic stability control, drive-by-wire.

Servers, Mainframes & Supercomputers

• Server: provides services to clients over a network.

  • Form factors: rack, blade, tower.

  • Dedicated server types (Table 3-1): application, backup, database, DNS, file/storage, FTP, game, home, list, mail, network, print, web, etc.

• Mainframe: large, powerful server supporting hundreds/thousands of concurrent users/transactions.

• Supercomputer: fastest, most powerful, room-sized, very expensive (half-million to multi-billion dollars).

Terminals & Kiosks

• Terminal: limited-power input/output device connecting to host.

  • Thin client: looks like PC but relies on server for processing.

  • POS (Point-of-Sale) terminals in retail.

  • ATM for banking.

  • Self-service kiosks (financial, photo, ticket, vending, visitor mgmt.).

Ports & Connections

• Port = interface for plugging peripheral.

• Connector attaches cable to port.

• Common ports/connectors (Table 3-4): DisplayPort, HDMI/mini HDMI, DVI, VGA, Thunderbolt, Lightning, USB-A/B/mini, FireWire, Ethernet, audio jacks.

• USB: daisy-chain up to $127$ devices on one controller.

• Mobile add-ons: port replicators, docking stations (provide extra USB, video, Ethernet, charging, etc.).

• Wireless peripheral links: Bluetooth, Wi-Fi, NFC.

Putting It All Together (Categories & Scale)

• Personal computers (desktop): $\text{Users} \approx 1$; price $\text{hundreds–thousands}\,$.

• Mobile computers/devices: fits on lap/hand; $\text{Users}=1$; price $\text{hundreds or less}$.

• Game consoles: usually one user; cost <$100–$1,000+>.

• Servers: small cabinet to room; $2 \rightarrow 1{,}000+\text{ users}$; cost $\text{hundreds–millions}$.

• Supercomputers: full-room; hundreds-of-thousands concurrent tasks; cost > half-million to $\text{billions}$.

• Embedded computers: invisible inside products; cost baked into product price.

Ethical, Practical & Real-World Notes

• Energy efficiency (cooling, low-power SoCs) critical for sustainability.

• Hardware reliability & protection vital for uninterrupted business processes.

• Mobile & cloud computing shift capital costs from ownership to service models.

• Embedded and IoT devices raise privacy/security issues (data collection, remote control).

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