1. Advanced Computer Applications
PC Types & Functions
Advanced Computer Applications
Lesson 2

2. DO NOW 9/8
List all the different types of computer devices that you use.
Briefly describe what you use each device for.

3. OBJECTIVES Identify the different computer types.
Define the four basic computer functions.
Describe computer input devices.
Understand the functions of a CPU.

4. The Computer “Computer” suggests computation or calculator
Electronic device that can manipulate data
Many have to do with numbers or math
To many people the word computer suggest “computation”, or calculator.
A computer is an electronic device – a flexible machine that can manipulate data. Many of these manipulations have to do with numbers or math.

5. Computer Types Most familiar is the PC
Indirect contact with other, larger computers
Supercomputer - science, mathematics, advanced computing, or military or industrial research
Fastest problem solvers available (high speed)
Process data in “parallel”
The computer you are most familiar with, and the one you will probably have the most direct contact throughout your, life, is the personal computer. But you will have indirect contact with other, larger computers.
If you make a career in science, higher mathematics, advanced computing, or military or industrial research, you may use a supercomputer. Supercomputers are the fastest problem solvers available. They work at extremely high speeds. Often, they process data in “parallel”, breaking a complicated problem into smaller units, each of which is handled by a part of the computer, then combined to produce the final results.

6. Mainframes Very powerful
Hundreds of people can use a mainframe at once
PCs or “dumb” terminals
Mainframes – are very powerful computers that can do many things at once. While only one person at a time can use a PC or a Macintosh, hundreds of people can use a mainframe at once.
If you work at a telephone company, you may use a PC to gain access to the large amounts of information stored under the control of a mainframe. You may also use a “dumb” terminal (keyboard and monitor) directly connected by networking wires to the mainframe. The terminals are called “dumb” because, unlike PC’s, they have no processing capabilities of their own but simply give users direct access to mainframe computing capacities.

7. Minicomputers Smaller processing & storage management than mainframes
Accessed also from dumb terminals or PC’s
Distinction between the two has broken down in recent years (growth of the PC)
Computer chips/storage capacities have increased rapidly
Networking
Minicomputers used to be distinguished from mainframe computers because they had smaller processing and storage management capabilities. The distinction has broken down in recent years for two reasons (which have also contributed to the growth of the PC).
Computer chips and storage capacities have increased rapidly and small machines can now manage much more storage and process much more rapidly than earlier ones.
Minicomputers are often linked in networks so companies (and universities, in particular) can use several networked minicomputers to perform the same tasks as one mainframe. Access to minicomputers, like access to mainframes, may be through dumb terminals or PC’s.

8. Computer Types
Desktop Computer Laptop PDA (Personal Digital Assistant)
Desktop Computer - is designed to remain in one location. The Personal Computer (PC) and the Macintosh support one user at a time.
PDA - (Personal Digital Assistant) is a computer that is small enough to hold in one’s hand.
Laptop – computer is designed to be carried from place to place. They grow lighter and sturdier with each new version. Laptops are compact with built-in liquid crystal display monitors that provide crisp displays. Their portability makes them ideal for sales people and other business professionals who travel a great deal.

9. Computer Types
Smartphone E-reader Tablet

10. Four Basic Functions: INPUT Keyboard Mouse Scanner Voice Microphone
PROCESSING
CPU
RAM
ROM
OUTPUT
PRINTER
MONITOR
STORAGE
CD-ROM
CD-RW
CD-DVD
DISKETTES
FLASH DRIVES
HARD DRIVE
TAPE

11. Input Devices
Keyboard Standardized layout Some change the location of certain keys or include keys that other keyboards do not Special keys (Function, Ctrl, Alt)
Keyboard
Is an input device with alphabetic, numeric, and function keys in a standardized layout. (Some keyboards change the location of certain keys and include keys that other keyboards do not.) The special keys (such as function , Ctrl, and Alt keys) are used alone or in combinations to cause programs to perform actions.

12. Input Devices Mouse Control a pointer that displays on the monitor
Is an input device that you move around on a surface to control a pointer that displays on the monitor. When the pointer is located at the spot where you want the software to respond, you click the left button one (click), the right button (right-click), or the left button twice rapidly (double-click)

13. Input Devices Scanners Create files from pictures or text
Optical Character Recognition (OCR)
Voice input
Microphones
Scanners
Let you create files from pictures or drawings or text.
They are known as input devices.
Voice input
Devices that are becoming more common as hardware and software makers are working to improve their efficiency.
Microphones are examples of this.

14. PC Internal Components
CPU – (Central Processing Unit)
Brain of the computer
Control Unit
ALU
Registers
CPU – (Central Processing Unit) is the brain of the computer system. It is made up of three main parts:
Control Unit
ALU
Registers

15. CPU

16. Control Unit
Controls and coordinates program instructions & processing of data
Determines which devices have access to various parts of the system
Tell the ALU and registers how to operate, what to operate on, and what to do with the result
Control Unit – is the portion of the CPU that controls and coordinates program instructions and the processing of data. This is the brains of the computer and determines which devices have access to various parts of the system. The control Unit is one of the most important parts of the microprocessor because it is in charge of the entire process. Based on instructions from the Decode Unit, it creates control signals that tell the Arithmetic Logic Unit (ALU) and the Registers how to operate, what to operate on, and what to do with the result. The Control Unit makes sure everything happens in the right place at the right time.

17. Arithmetic Logic Unit
Performs and controls all arithmetic and logical operations
Relieves the control unit of most of the arithmetic functions
Performs +, -, *, /
Logic commands: AND, OR, and NOT
Takes data from registers
ALU – (Arithmetic Logic Unit) is the portion of the CPU that performs and controls all arithmetic and logical operations. Computer operations are fundamentally a set of mathematical computations and therefore, require a great deal of processing. The ALU relieves the control unit of most of the arithmetic functions. The ALU is the last stage of processing in the chip. The ALU is the smart part of the chip that performs commands like adding, subtracting, multiplying, and dividing. It also knows how to read logic commands like OR, AND, or NOT. Messages from the Control Unit tell the ALU what it should do and then it takes data from its close companion, the Registers, to complete the task.

18. Registers Storage area for data used by the ALU
Complete the tasks by the Control Unit
Data stored at special locations within the Registers
Retrieval for the ALU quick and efficient
Registers– are a mini-storage area for data used by the Arithmetic Logic Unit (ALU) to complete the tasks the Control Unit has requested. The data can come from the data cache, main memory or the control unit and are all stored at special locations within the Registers. This makes retrieval for the ALU quick and efficient.

19. Random Access Memory (RAM)
Where programs and data reside while in use
Excel example
Saving a document: RAM to permanent storage
Loss of power information in RAM is lost
RAM capacity is measured in megabytes
RAM– (Random Access Memory), special chips connected to the CPU, is the area where programs and data reside while in use.
When you start an application (Excel for example), the computer places the program into RAM. If you then open a document, it also loads the document into RAM.
When you save a document, the CPU copies the document in RAM to permanent storage. When you close a document, the CPU frees up the memory that was occupied by the document. When you close a program, memory is freed up.
RAM holds information only so long as it has electricity. If the machine is turned off or loses power, information in RAM is lost. That's why any changes not saved before the machine is turned off cannot be retrieved.
In modern PC’s, RAM capacity is measured in megabytes.

20. PC Internal Components
Is more RAM necessary? – The amount of RAM in a PC can have a big effect on the computer’s power. When the PC needs access to other parts of a program or data on the disk it can unload, or swap out, nonessential parts from RAM to the hard disk. Then the PC can load, or swap in, the program code or data it needs. While this is an effective method of managing a limited amount of memory, the computer’s system performance is slower because the CPU, memory, and disk are continuously occupied with the swapping process. More RAM can mean the PC can use bigger, more powerful programs that can access bigger data files. More RAM can also make the PC run faster because it will need to swap instructions between RAM and the hard disk much less often.
Is more RAM necessary? – The amount of RAM in a PC can have a big effect on the computer’s power. When the PC needs access to other parts of a program or data on the disk it can unload, or swap out, nonessential parts from RAM to the hard disk. Then the PC can load, or swap in, the program code or data it needs. While this is an effective method of managing a limited amount of memory, the computer’s system performance is slower because the CPU, memory, and disk are continuously occupied with the swapping process. More RAM can mean the PC can use bigger, more powerful programs that can access bigger data files. More RAM can also make the PC run faster because it will need to swap instructions between RAM and the hard disk much less often.

21. Read Only Memory (ROM) Memory read from but not written to
Non-volatile memory
Computer start-up (BIOS, CMOS, POST)
ROM access slower than RAM
ROM is memory that is capable of holding data and being read from; however, it is not capable of being written to or having its data modified. Unlike RAM, ROM is non-volatile and capable of keeping its contents regardless if it has power or not.
This type of memory lets you stored the data needed to start up the computer. Indeed, this information cannot be stored on the hard disk since the disk parameters (vital for its initialization) are part of these data which are essential for booting. Different ROM-type memories contain these essential start-up data, i.e.:
The BIOS is a program for controlling the system's main input-output interfaces, hence the name BIOS ROM which is sometimes given to the read-only memory chip of the mother board which hosts it.
The bootstrap loader: a program for loading (random access) memory into the operating system and launching it. This generally seeks the operating system on the floppy drive then on the hard disk, which allows the operating system to be launched from a system floppy disk in the event of malfunction of the system installed on the hard disk.
The CMOS Setup is the screen displayed when the computer starts up and which is used to amend the system parameters (often wrongly referred to as BIOS).
The Power-On Self Test (POST), a program that runs automatically when the system is booted, thus allowing the system to be tested (this is why the system "counts" the RAM at start-up).
Given that ROM are much slower than RAM memories (access time for a ROM is around 150 ns whereas for SDRAM it is around 10 ns), the instructions given in the ROM are sometimes copied to the RAM at start-up; this is known as shadowing, though is usually referred to as shadow memory).

22. PC Internal Components
ROM– (Read-Only Memory) is a higher grade, more expensive kind of memory that retains data even when the computer is turned off. ROM is “built in” or “hard wired” computer memory containing data that normally can only be read, not written to. ROM contains the instructions that allow your computer to be “booted up” or regenerated each time the PC is turned on. Unlike RAM, the data in ROM is not lost when the computer power is turned off. If you ever do the hardware setup procedure to your PC, you effectively will be writing to ROM.
ROM– (Read-Only Memory) is a higher grade, more expensive kind of memory that retains data even when the computer is turned off. ROM is “built in” or “hard wired” computer memory containing data that normally can only be read, not written to. ROM contains the instructions that allow your computer to be “booted up” or regenerated each time the PC is turned on. Unlike RAM, the data in ROM is not lost when the computer power is turned off.
If you ever do the hardware setup procedure to your PC, you effectively will be writing to ROM.

23. Famous Persons in Computer History
Work on your projects with your partner.
Due Thursday 9/11
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