2.1.4 Distinguish between logical I/O and physical I/O

2.1.4 Distinguish between logical I/O and physical I/O

logical input relate to hard disk

Logical I/O an Physical I/O

• Physical" I/O is an actual fetch of data from a storage device such as a disk.
• Logical" I/O is a programmatic request for data satisfied by a memory (block, buffer) access.
• A logical I/O may cause a physical I/O in the first place, or a logical I/O may retrieve a part of a block (buffer) of data from memory.

2.1.5 Distinguish between directory management and disk space management.

Directory management

• A directory is a hierarchical collection of directories and files. 
• The only constraint on the number of files that can be contained in a single directory is the physical size of the disk on which the directory is located.

Disk management

• A hard disk is a rigid disk inside a computer that stores and provides relatively quick access to large amounts of data. It is the type of storage most often used with Windows. The system also supports removable media.
• Hard disk can contain one or more logical regions called partitions. Partitions are created when the user formats a hard disk as a basic disk hard disk can contain one or more logical regions called partitions. Partitions are created when the user formats a hard disk as a basic disk.
• The creation of multiple partitions on a drive allows the appearance of having separate hard drives. For example, a system with one hard disk that has one partition contains a single volume, designated by the system as drive C. A system with a hard disk with two partitions typically contains drives C and D. 
• Having multiple partitions on a hard disk can make it easier to manage the system, for example to organize files or to support multiple users.

2.1.6 Identify the primary functions performed by input/output control system.

• Input/Output Control System (IOCS) is any of several packages on early IBM entry-level and mainframe computers that provided low level access to records on peripheral equipment. 
• IOCS provides functionality similar to File Control Processor (FCP) in RCA 3301 Realcom Operating System and GEFRC in GECOS.

Input

Input is anything we wish to embed in a system for some type of use. A variety of sources are used to input: keyboard, scanner, microphone, mouse, even another computer. 

Output

• Output, or processed information in a usable format, comes in many different forms: monitor or printer for visual work, a speaker for audio. 
• Sometimes our output is short-term, such as printing a photo, and sometimes what we work on needs to be kept around for a while. That's where storage comes in

2.1.7 Describe the boot process.

Definition of boot process

Boot process is a process or starting or restarting of computer. There 2 types of boot process

Cold boot 

Turning on computer that has been powered off

Worm boot

Restarting computer that is powered on 

A personal computer boot up process

Step 1. Power supply sends signal to components in system unit

Step 4. Results of POST are compared with data in CMOS chip

Step 2. Processor accesses BIOS to start computer

Step 3. BIOS runs tests, called the POST, to check components such as mouse, keyboard, and 

adapter cards 

Step 5. BIOS looks for system files on a USB drive, in floppy disk drive or CD/DVD drive, and then 

hard disk

Step 6. Kernel (core) of operating system loads into RAM

Step 7. Operating system loads configuration information and displays desktop on screen