What is a Computer System

INFO

A computer system combines the computer hardware and special system software that together make the computer usable by users and programs

• Input/Output (IO) Ports → enable the computer to take information from its environment and display information to the user in some meaningful way
• Central Processing Unit (CPU) → runs instructions and computes data and memory addresses
• Random Access Memory (RAM) → stores the data and instructions of running programs. The data and instructions in RAM are typically lost when the computer system loses power
• Secondary Storage Devices → Things like hard disks stores programs and data even when power is not actively provided to computer
• Operating System (OS) → The layers between hardware of the computer and the software that a user runs on the computer
  • Implements programming abstractions and interfaces → enable users to easily run and interact with programs on the system
  • Manages the underlying hardware resources and controls how and when programs execute
  • Implements abstraction to ensure that multiple programs can simultaneously run on the system in an efficient, protected, and seamless manner

IMPORTANT

The Input/Output (IO) ports, Central Processing Unit (CPU), Random Access Memory (RAM), and Secondary Storage Devices defines the computer hardware component of a computer system The Operating System represents the main software part of the computer system

Focus specifically on computer systems that:

• General Purpose → their function is not tailored to any specific application
• Reprogrammable → supports running a different program without modifying the computer hardware or system software

What Do Modern Computer Systems Look Like?

Typically 2 types of computer hardware systems:

• Desktop Computer (left)
  • The DVD/CD bay was moved to the side to show the hard drive underneath — the 2 units are stacked on top of each other
  • Dedicated power supply helps provide the desktop power
  • Power: 100W - 400W
  • Weight: 5lb - 20lb
• Laptop Computer (right)
  • Flatter and more compact
  • Components tend to be smaller
  • has battery instead of power supply → uses an external charger to supplement the battery as needed
  • Power: 50W - 100W

What is common between the 2?

• The CPU is obscured by a heavy weight CPU fan, which helps keep the CPU at a reasonable operating temperature → overheating = permanent damage
• Has Dual Inline Memory Modules (DIMM) for their RAM units
  • Laptop’s is significantly smaller than the Desktop’s

NOTICE

Both contain the same hardware components, thought some of the components may have a smaller form or be more compact

Raspberry Pi

IMPORTANT

The trend in computer hardware design is toward smaller and more compact devices

• Single-Board Computer (SBC): a device in which the entirety of the computer is printed on a single circuit board
• Contains a System-On-a-Chip (SOC) processor with integrated RAM and CPU
  • Encompasses much of the laptop and desktop hardware
  • This technology is also commonly found in smartphones
• Roughly the size of a credit card
• Weighs: 1.5oz
• Power: 5W

Multicore Processors

The computer systems mentioned above (Raspberry Pi, Laptops, and Desktops) including smartphones have multicore processors

• Their CPUs are capable of executing multiple programs simultaneously → Parallel Execution