# CIS105: Computer Applications & Information Systems Lect. 5

## Chapter 5: Operating System

### 5.1: Operating System Fundamentals

-   1980: Bill Gates and Paul Allen leased IBM a Personal Computer (PC) called MS-DOS (Microsoft Disk Operating System) for a one-time fee of $\$50,000$.
    -   Gates Kept the copyright for MS-DOS
-   1984: Steve Jobs and Steve Wozniak created Mac OS
    -   Advertised on "More user-friendly"

### 5.2: Understanding Operating Systems

-   System software: Software that automatically runs to configure a computer (no human intervention)
-   Operating system (AKA Platform): A collection of computer programs that administer the hardware and software of a computer so that they work properly
    -   Microsoft Windows, Mac OS, UNIX, Linux
-   **Application software cannot run or be installed without a operating system**.

### 5.3: Memory Management

-   **Operating system coordinate**: Computers memory

    -   **Cache, Random Access Memory (RAM), registers, and virtual memory**
    -   **Disk Storage**

-   **CPU Cache**: A small, very quick memory that stores copies of information and data from the most regularly-used parts of main memory

    -   Helps decrease the time it takes to access memory.

-   **Random Access Memory (RAM)**: Volatile memory

-   Disk Storage: Non-volatile memory

    -   > **volatile memory stores data when a computer is on but erases it as soon as the computer is switched off, whereas non-volatile memory remains in a computer even after the system shuts off**.

### 5.4: Memory Management Contd.

-   Registers: Small memory locations used to quicken the implementation of computer programs
    -   Customization towards the device including wallpaper setting which is referred the process of registering.
-   Virtual Memory: Memory the OS uses to coordinate, track and efficiently allocate the use of CPU cache, registers, RAM and disk storage.
    -   The messenger between volatile and non-volatile storage.

### 5.5: Disk Management

-   OS is responsible for saving information as efficiently as possible
    -   Creates a table of contents of FAT (File Allocation Table)
-   Defragmentation: A program the reorganizes the hard drive
    -   Note required for SSD
-   Hard Disk Drive (HDD)
    -   Pros: More affordable, good for standard business procedures
    -   Cons: more prone to damage
-   Solid State Drives (SSD)
    -   Pros: N moving parts, more reliable
    -   Cons: More expensive.

### 5.6: File Management

-   File manager are made up of Hierarchy of Directories, more commonly referred to as folders
    -   Can be compared to a physical storage

### 5.7: Networks

-   Network: 2 or more computers connected together
-   Transmission control protocol and internet protocol (TCP/IP): A set of rules for transferring information from one computer to another
    -   Transfers info by breaking up files into packates
-   The internet is the world's largest network

### 5.8: Device Drivers

-   Device Driver: Allows the OS to communicate with peripheral devices
-   Modern OS have plug-and-play capability
-   1996: USB developed and considered industry standard

### 5.9: embedded Operating Systems

-   Embedded Operating System: OS installed on devices and appliances that rely on computing
    -   Ex; Cash registers, automatic teller machines (ATM), microwaves, and specialized handled devices
    -   Embedded OS cannot be modified in most cases
    -   Embedded OS used on most cell pones
        -   Google, Android, and iPhone

### 5.10: Mac or PC?

-   The answer is baed on the needs of the business
-   Ask yourself: Which one are your end-users comfortable or have experiencing using? Which one gives you a clear competitive advantage?

### 5.11: Major Operating Systems

-   Microsoft Windows: Windows 10
    -   Windows 11 available for download
-   Mac Operating System (AKA Mac OS)
    -   Version 14: Sonoma
-   Linux: An open-source OS that can be modified, used, and redistributed by anyone freely
    -   Created by **Linux Torvalds**
-   UNIX: Popular for large processing applications like credit card transactions and approvals.

### 5.12: Open-Source OS

-   Proprietary software vs. open-source
    -   Why doesn't everyone use open-source
-   Diffusion: A product or software is widely accepted