1. ASICS
An ASIC (application-specific integrated circuit) is a microchip designed for a special application, such as a particular kind of transmission protocol or a hand-held computer. You might contrast it with general integrated circuits, such as the microprocessor and the random access memory chips in your PC. ASICs are used in a wide-range of applications, including auto emission control, environmental monitoring, and personal digital assistants (PDAs).
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2. An application-specific integrated circuit, is an integrated circuit (IC) customized for a particular use, rather than intended for general-purpose use.
An ASIC can be pre-manufactured for a special application or it can be custom manufacture for a particular customer application.
For example, a chip designed to run in a digital voice recorder is an ASIC.
Application-specific standard products (ASSPs) are intermediate between ASICs and industry standard integrated circuits like the 7400 or the 4000 series.
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3. an ASIC has grown from 5,000 gates to over 100 million
an ASIC has grown from 5,000 gates to over 100 million. Modern ASICs often include entire microprocessors, memory blocks including ROM, RAM, EEPROM, Flash and other large building blocks. Such an ASIC is often termed a SoC (system-on-chip)
 Designers of digital ASICs use a hardware description language(HDL), such as Verilog or VHDL, to describe the functionality of ASICs.
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4. HISTORY OF ASICS The initial ASICs used gate array technology.
 Ferranti produced perhaps the first gate-array, the ULA (Uncommitted Logic Array), around 1980.
An early successful commercial application was the ULA circuitry found in the 8-bit ZX81 and ZX Spectrum low-end personal computers, introduced in 1981 and These were used by Sinclairv Research (UK)
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5. Due to Customization occurred by varying the metal interconnect mask
Due to Customization occurred by varying the metal interconnect mask. ULAs had complexities of up to a few thousand gates.
Gate Array Design:
Gate-array design is a manufacturing method in which the diffused layers, i.e. transistors and other active devices, are predefined and wafers containing such devices are held in stock prior to metallization in other words, unconnected.
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6. Gate-array ASICs are always a compromise as mapping a given design onto what a manufacturer held as a stock wafer never gives 100% utilization.
Often difficulties in routing the interconnect require migration onto a larger array device with consequent increase in the piece part price.
These difficulties are often a result of the layout software used to develop the interconnect.
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7. ASICS SUPPLIERS
There are two different types of ASIC suppliers, IDM and fabless.
IDM ASIC suppliers
Allegro
AMS
Avago Technologies
Elmos Semiconductor
Cavium Networks
Fujitsu
Freescale Semiconductor
HITACHI
Global Foundries
IBM
Infineon Technologies
GigOptix (ChipX Structured ASIC)
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8. Maxim Integrated Products NEC NXP Semiconductors ON Semiconductor
LSI Corporation
Maxim Integrated Products
NEC
NXP Semiconductors
ON Semiconductor
Renesas
Samsung
STMicroelectronics
Texas Instruments
Toshiba
TSMC
Bosch
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9. Fabless ASIC suppliers Alchip Aeroflex Colorado Springs
AnSem (Analog, RF and mixed-signal ASICs)
Brite Semiconductor
Broadcom Corporation
Custom Silicon Solutions, Inc.
GigOptix (ChipX Structured ASIC)
DA-Integrated
DELTA Microelectronics
eASIC
eSilicon
Faraday Technology
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10. Hong Kong Science and Technology Parks Corporation
ICsense (ASIC Design and Supply)
Marvell Semiconductor
MOSIS
Nvidia
Open-Silicon
PMC Sierra
Qualcomm
SWINDON Silicon Systems
Socle Technology Corporation
Triad Semiconductor (Configurable Analog and Mixed-Signal)
Xilinx
Cactus Semiconductor
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11. COMPUTER
Computer is an electronic device that perform some arithmatic and logic operation to achive specific task.
Computer works mostly on data and information.
Data is a collection of raw facts.Data may be valuable or non-valuable.
Information is the processed data.
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12. Major Components Of A Digital Computer
CPU
Input Device
Output Device
Memory
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13. Control Unit CPU ALU Accumulator The CPU is the brain of the computer
Its primary function is to execute programs.
It also control the operation of all other components such as memory, input & output devices.
ALU
Accumulator
General &
Special Purpose
Register
Control Unit
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14. CONTROL UNIT
It control the entire operation of the computer by passing control signals.
It gives order to ALU what operation is to be performed .
It controls the data flow between the CPU & Peripherals.
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15. Characteristics Of Computer
Speed
Accuracy
Reliability
Storage Capability
Automation
Versatility
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16. Characteristics Of Computer
Computers are built to carry out a small variety of instruction.
Instruction are extremely simple e.g. add,subtract,read or write chracter,compare a no. etc.
Most instruction are carried out in less than a millionth of a second.
Instructions are carried out obediently with no question asked.
Instructions are carried out without any mistakes.
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17. Disadvantages of computer
Computer does no work by itself. It works on the basis of the list of instruction given to it.
Computer doesnot have any I.Q it works on the basis of what has been instructed.
Computer does not take decision of its own.
Computer does not learn by experience.
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18. ALGORITHM
It is a step by step description of how to arrive at the solution of the given problem.
An algorithm may be defined as a finite sequence of instruction to solve a problem.
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19. Characteristics of algorithm
An algorithm begins with instruction to accept input.
The proceesing rules specified in the algorithm must be precise and unambiguous.
Each instruction must be carried out by a person with paper and pencil.
The total time to carry out all the steps in the algorithm must be finite.
An algorithm must produce one or more outputs.
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20. Example of algorithm
an algorithm to find the avg no. of vowels in a passage.
Step 1: Let no. of character=0
Step2: Let no. of vowels=0
Step3: Repeat 4,5,6 and 7 until end of passage is reached.
Step4: read one character from passage.
Step5: add 1 to no. of character.
Step6:if the character is any one of the letters A,E,I,O,U,a,e,I,o,u add 1 to no. of vowels.
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21. Step7:move to next character. Step8: avg no. of vowels = no
Step7:move to next character. Step8: avg no. of vowels = no.of vowels/no. of character Step9: Write avg no.of vowels. Step10: stop.
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22. Flow Chart It is a pictorial representation of an algorithm.
Processing
Start/Stop
INPUT/OUTPUT
Decision Box C
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23. Input Devices
These are those devices, which facilitate a user to give input. Information is entered in to a computer through input devices.
An input device converts input information in to suitable binary format, which can be accepted by the computer system.
The computer system has to process details of each command, therefore the command will have to be converted in to machine readable format and this work can be done through input unit.
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24. Keyboard Keyboard is one of the most widely used peripheral devices.
Data is entered in to the computer system through keyboard.
Keyboards are designed for the input of text and characters and also to control the operation of a computer.
Most of the keyboard have a common number of features like:
Standard type writer keys
Function keys
Special purpose keys
Cursor Movement Keys
Numeric keys
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25. MOUSE
Mouse is a device which is used to move the cursor on the screen and to select options.
When the mouse is moved on the surface the cursor is also moved in the same direction on the monitor.
By moving the mouse the user can point to menu on the screen i..e. Mouse is also known as pointing device.
Pressing the button of a mouse is known as clicking. Technicians often describe mouse speed in DPI(dots per inch).
One DPI is intended to be the number of pixels the mouse cursor will move when the mouse is moved one inch.
Some common types of mouse are
Mechanical Mouse
Optical Mouse
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26. LIGHT PEN
A light pen is a pointing device.It is an input device in the form of a light-sensitive wand used in conjunction with the computer's CRT monitor.
It allows the user to to select a displayed menu option on the CRT.
A light pen can work with any CRT-based monitor, but not with LCD screens, projectors or other display devices.
It is capable of sensing a position on the screen when its tip touches it ,its photocell sensing element detects the light coming on the screen and sends the corresponding signal to the processor.
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27. TOUCH SCREENS
It is a type of display screen in which one can use finger to point the command displayed on the screen. In this user touches the icon that represent their choices and the computer display information about their choices.
There are some types of touch screen technology:
A resistive touch screen panel is coated with a thin metallic electrically conductive and resistive layer that causes a change in the electrical current which is registered as a touch event and sent to the controller for processing.
Surface wave technology uses ultrasonic waves that pass over the touch screen panel. When the panel is touched, a portion of the wave is absorbed. This change in the ultrasonic waves registers the position of the touch event and sends this information to the controller for processing.
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28. JOYSTICK A joystick is also a pointing device.
It is used to move cursor on the CRT screen.
A joystick is a stick that has spherical ball at it’s upper as well as its lower end.
The lower spherical ball moves in a socket.
The electronic circuitry inside the joystick detects and measures the displacement from its central position, the information is sent to the processor.
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29. MICR
Magnetic Ink Character Recognition, or MICR, is a special kind of character recognition technology that was adopted mainly by the banking industry to facilitate the processing of cheques.
A special ink called magnetic ink is used to write the character of the cheques and deposit forms which are to be processed by an MICR.
The magnetic ink is magnetized during the input process.
The MICR reads these pattern and compared with the special pattern stored in the memory
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30. OCR(Optical Character Reader)
It is an abbreviated form of Optical Character Reader. It detects the alphanumeric character printed on paper.
It works on the basis of light scanning techniques in which each character is illuminated by the light source and the reflected images of the character is received by the photocells which provides binary data corresponding to the lighted and dark areas.
OCR is quite costly because the memory requirement is very high.
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31. BAR CODE READER
Bar code is a machine readable numerical code, printed as a set of varying width vertical bars.
A barcode reader is a computer peripheral for reading barcodes printed on various surfaces.
As you know bar codes are present on most of the grocery item, it consist of a number of thick lines with a varying distance between them.
A barcode reader scans the bar code, and converts it into a number that the computer can then process and display on the screen.
Bar code reader, generally consists of a light source, a lens and a photo conductor translating optical impulses into electrical ones. Therefore, it read such bars and convert thm in to electrical pulses which is processed by the computer.
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32. OMR
Special marks such as square or bubble are prepared on examination answer sheets.
The user fill in theses squares or bubbles with soft pencil or ink to indicate there choices. These squares are detected by an OMR and the corresponding signals are sent to the processor.
If a mark is present, it reduces the amount of reflected light . If a mark is not present the amount of light reflected is not reduced.
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33. OUTPUT DEVICES
The output devices receive information from the computer and provide them to user in a readable format. The computer sends information to the output devices in binary coded forms. Then, output devices convert them in to a form, which can be used by user. Some output devices are
Printer
Monitor
Plotter
Speaker
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34. PRINTER
It is a device that produces a hard copy which is permanent human-readable text of documents stored in electronic form, usually on physical print media such as paper or transparencies.
The data received by a printer may be:
a string of characters
a bitmapped image
a vector image
Printers which are used with computer can be classified in two ways.
Line Printer
Character Printer
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35. Line printer is categorised into: Drum Printer Chain Printer
Comb Printer
In drum printers, a drum carries the entire character set of the printer repeated in each column that is to be printed. The printer receives all characters to be printed in one line of the text from the processor. The hammer hit the paper and ribbon against the desired character on the drum when it comes in the printing position.
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36. A AAAAAAAAAAA
BBBBBBBBBBBBB
In chain printers which is also known as train printers, the character set is arranged multiple times around a chain that travels horizontally past the print line. In either case, to print a line, precisely timed hammers strike against the back of the paper at the exact moment that the correct character to be printed is passing in front of the paper. The paper presses forward against a ribbon which then presses against the character form and the impression of the character form is printed onto the paper.
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37. Another way of classifying the printer is on the basis of manufacture:
In comb printers, a comb of hammers printed a portion of a row of pixels at one time. By shifting the comb back and forth slightly, the entire pixel row could be printed.
Another way of classifying the printer is on the basis of manufacture:
Impact Printer
Non Impact Printer
Impact printer use electromechanical mechanism that causes hammer or pin to strike against a ribbon and a paper to print the text.
Non Impact Printer, A printer that creates an image without striking a ribbon against the paper.It does not use electromechanical printing head to strike against ribbon and paper.These type of printer use thermal, chemical, electrostatic, laser beam or inkjet technology for printing the text.
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38. DOT MATRIX PRINTERS
It use a matrix of small pins to create precise dots.
In this character is printed by printing the selected no of dots from a matrix of dot. The formation of a character has been shown 5 dot rows and 7 dot columns. This pattern is called 5*7 dot matrix. In this character is printed by printing the selected no of dots from a matrix of dot. The formation of a character has been shown 5 dot rows and 7 dot columns. This pattern is called 5*7 dot matrix.
Such printers would have either 9 or 24 pins on the print head. Print head is that part of the printer that creates the printed image.
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39. INKJET PRINTER
It is a type of non impact printer. It is a printer that creates an image by spraying tiny droplets of ink from the printhead.
In ink-jet printer, whenever we want to print the image the nozzel spread the ink, so there is a permanent remark on the paper. Suppose there is a 5 pin then it spread the ink up to 5 pixels. But it can approximately print up to 16 to 32 pixel at a time.
In inkjet printer the ink is stored in a cartridge.A colour inkjet printer cosist of four cartridge one each for blue, green, cyan, magenta and black.
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40. LASER PRINTER
Laser printer are page printer. They make use of laser beam to produce an image of the page containing text /graphics on a photo sensitive drum.
A laser printer uses a rotating disc to reflect laser beam onto a photosensitive drum, where the image of the page is converted in to an electrostatic charge.
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41. PLOTTER Plotter used to produce good quality drawings and graphs.
Drum plotter: It contain along cylinder and a pen carriage. The paper is placed over the drum. The drum rotates back and forth. The pen moves horizontally along the surfacei.e either left to right or right to left.
Flat-Bed Plotter: It uses horizontal flat surface on which paper is fixed and the pen moves along both the axes i.e. x axis and y axis.
Inkjet Plotter: These plotter uses inkjet in place of ink pens.
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42. Refreshing Rate = 1/Refreshing Time
VDU(VIDEO TERMINAL)
A computer display is a device that can display signals generated by a computer as images on a screen.
Quality factors used in monitor are:
Pixels: It is the smallest unit of monitor which is displayed without disturbing the other point .While designning the pixels, some distance between the pixels must be there in the horizontal as well as in vertical directin also.
Aspect Ratio: It is the ratio of the pixels in the horizontal as well as in vertical direction also.
Resolution: No of pixels in a per unit area.
Refreshing Rate: The rate by which the pixels glow again
Refreshing Rate = 1/Refreshing Time
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43. VDU IS CATEGORIZED INTO
CRT
Non CRT
CRT Display
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44. Non CRT Display
LCD
LED
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45. SPEAKER
Speaker is one of the output devices which is mainly used for entertainment, video conferencing etc.Computer speakers, or multimedia speakers, are external speakers and are usually equipped with a male-end stereo jack plug.
The sound capability of the computer system does not work unless and unti there is a sound card. Speaker recieves the data from the sound card in the form of electric signal and then convert it in to the sound format
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46. Technical Evolution Of Computer
First Generation
Second Generation
Third Generation
Fourth Generation 1971-Present
Fifth Generation Present-Future
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47. First Generation Computers
The era of the first generation computers began in 1946 because that was the year when people consciously set out to build stored program computers. In 1946 there was no 'best' way of storing instructions and data in a computer memory. There were four competing technologies for providing computer memory:
Electrostatic storage tubes,
Acoustic delay lines (mercury or nickel),
Magnetic drums (and disks),
Magnetic core storage.
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48. Some computers of these generations are given below:
ENIAC
EDVAC
EDSAC
UNIVAC
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49. Characteristics of First Generation Computers
Used vaccum tubes
Not reliable
Big and clumsy computers
Electric consumption is very high
This type of computers generate too much heat, therefore air conditioners are required.
Batch processing
Slow Input/Output operations.
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50. Second Generation Computers
Transistor takes place of vaccum tubes.
Faster than first generation.
Assembly language is used instead of machine language.
Generate less heat
Smaller in size
Magnetic tapes and disks are used.
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51. Third Generation Computers
Transistors is replaced integrated circuits
Increases speed as well as reliability.
Uses multiprogramming operating system
Lower power consumption
Magnetic disk can be used as a secondary storage.
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52. Fourth Generation Computers
Very large scale and ultra large scale integrated circuits has been developed.
Computers now becomes portable.
Semiconductor can be used as primary storage.
Database Management system can be used
Distributed data processing.
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53. Fifth Generation Computers
Fifth generations computers are only in the minds of advance research scientists and being tested out in the laboratories. These computers will be under Artificial Intelligence (AI), They will be able to take commands in a audio visual way and carry out instructions. These computers will perform many of the operations, which require low human intelligence.
Parallel Processing is coming and showing the possibility that the power of many CPU's can be used side by side, and computers will be more powerful than those under central processing. Advances in Super Conductor technology will greatly improve the speed of information traffic. Future looks bright for the computers.
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54. Description Of a Processor
The processing unit in a computer interprets instructions given in a program and carries out the instructions.
Processors are designed to interpret a specified number of instruction codes. Each instruction code is string of binary digits.
All processors have input/output instructions, arithmetic instructions, logic instructions, branch instructions and instructions to manipulate characters.
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55. In this section we will describe the processor of a hypothetical computer which we will call HYPCOM. The processor of HYPCOM has an accumulator register (ACC). The other registers are an instruction register (IR) and a program counter register (PC).
The instruction register is used to temporarily store the instruction being executed. It consist of two parts :
An operation code part
Address part
The PC register stores the address of the next instruction to be executed.
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56. The other specifications of HYPCOM are :
It has a 4K word addressable memory.
A word of HYPCOM is 16 bits long.
A word of HYPCOM stores either an instruction or data to be processed.
It has 15 operation codes.
The instructions are single address instructions. Four bits are needed to represent 15 operation codes. Twelve bits are needed to address a 4K memory
An instruction is thus 16 bits long.
6) It has an input unit which is used to feed both instructions and data.
A 16 bit word is read via the input and stored in memory when a READ operation
code is executed by the processor.
7) It has a printer as its output unit which is used to output a 16 bit word from the
memory when a PRINT operation code is executed by the processor.
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57. ADD to the accumulator contents of specified address. SUB
CLA:
Clear accumulator and place contents of specified memory address in it.
ADD
ADD to the accumulator contents of specified address.
SUB
Subtract from the accumulator contents of specified address
MUL
Multiply contents of accumulator by contents of specified address.
DIV
Divide the contents of accumulator by the contents of specified address
and leave integer quotient in accumulator.
STO
Store contents of accumulator in the specified address in memory.
JMP
Take next instruction from address 653 of memory.
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58. from address given in PC. JZE
JNE
Take next instruction from address 446 if ACC<0 else next instruction
from address given in PC.
JZE
Take next instruction from the address 648 if ACC=0 else next instruction
from the address given in PC.
READ
Input into specified address in memory data read from input unit.
PRINT
Print data retrieved from the specified address in the memory.
SHR
Shift contents of ACC right by 8 bits.
COM
Complements contents of ACC.
EOR
Match each bit of ACC with each bit of contents of specified address.
HLT
Halt computation
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59. COMPUTER LANGUAGE
Computer programming languages are developed with the primary objective of facilitating a large no. of people to use computers without the need to know in detail the internal structure of computer.
Languages are matched to the type of operations to be performed in algorithms for various application.
Languages are also designed to be machine-independent.
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60. A. Machine Language
Machine language is a system of instructions and data which is directly understandable by a computer's central processing unit. In this instructions are patterns of bits. Depending on the processing architecture, a given instruction may specify:
Particular registers for arithmetic, addressing, or control functions
Particular memory locations or offsets
Particular addressing modes used to interpret the operands
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61. Advantages Of machine Language
The machine easily understands these languages.
Processing is faster.
Limitations Of Machine Language
It is machine dependent; it is different from one computer to another.
All the instructions are to be given into binary digits, therefore it is very difficult to program.
It is difficult to rectify a program written in machine language.
It is very time consuming and tedious task to write a program in machine language.
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62. B. Assembly Language
Writing the programs in machine language is a very tedious and boring job. To solve this problem, assembly languages is developed which makes use of alphanumeric symbols for writing the set of instruction instead of 0 and 1.
A program written in assembly language consists of a series of instructions in symbolic code i.e. mnemonics that correspond to a stream of executable instructions, when translated by an assembler, that can be loaded into memory and executed.
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63. Advantages Of Assembly Language
Easy to understand because of mnemonic code.
Easy to detect and correct error.
Eassily modified
It saves time and reduce complexity than machine language program.
The computation time of assembly anguage program is less.
Limitations
The assembly language is machine oriented. This means that program must have the detailed knowledge of the structure of the computer.
Assembly language program contains more instruction as compared to high-level languages
Writing assembly language programs is difficult and time consuming..
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64. C. High Level Language Advantages Of High Level Language
It is a machine independent language.
They are easier to learn and understand.
Program written in this language are portable and easier to maintain.
In this program can be easily written because natural language English is used.
Limitations
The high level language program take more time to run.
Computer are unable to understand instruction given in high level language.
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65. OPERATING SYSTEM
An operating system is a program that control the execution of application programs and acts as an interface between the user of a computer and the computer hardware.
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66. Sunil Kumar Sahu,Lecturer RCET

67. OPERATING SYSTEM The structure of OS consists of 4 layers: Hardware
Hardware consists of CPU, Main memory, I/O Devices, etc,
Software (Operating System)
Software includes process management routines, memory management routines, I/O control routines, file management routines.
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68. This layer consists of compilers, Assemblers, linker etc.
System programs
This layer consists of compilers, Assemblers, linker etc.
Application programs
This is dependent on users need. Ex. Railway reservation system, Bank database management etc.,
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69. Services provided by OS
Program development
Program execution
Access to I/O devices
Controlled access to files
System access
Error detection and responses
Accounting
Resource allocation
Communication
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70. Functions of Operating Systems
Provide a user interface
Run programs
Manage hardware devices
Organized file storage
In a desktop computer, these resources include such things as the processor ,memory and disk space
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71. It provides a stable, consistent way for applications to deal with the hardware without having to know all the details of the hardware.
The OS also determines how you see information and perform tasks. Some operating systems utilize a graphical user interface (GUI), which presents information through pictures (icons, buttons, dialog boxes, etc.) as well as words.
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72. OS performs a variety of functions, including determining what types of software you can install.
coordinating the applications running on the computer at any given time
making sure that individual pieces of hardware, such as printers, keyboards, and disk drives, all communicate properly
allowing applications such as word processors, clients, and web browsers, to perform tasks on the system
reporting errors.
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73. Core Process Of Operating system
Process Management
Memory Management
File Management
Device Management
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74. The creation and deletion of both the user and system processes.
Process Management
The creation and deletion of both the user and system processes.
The suspension and resumption of process
The provision of mechanism for process synchronization
The provision of mechanism for dealock handling.
When a program is submitted to the CPU, it may be one of the three states:
Running
Ready
Wait
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75. Allocate and deallocate the memory space as needed.
Memory Management
Keep track of which part of the memory are currently being used and by whom.
Decide whichprocess is to be loaded in to the memory when the memory space becomes available.
Allocate and deallocate the memory space as needed.
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76. The creation and deletion of file.
File Management
The creation and deletion of file.
The creation and deletion of directories.
The mapping of file on to the secodary storage.
The backup files on stable storage media.
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77. Device Management
It should activate them, control them, issue command to the device, handle errors etc.
It should also provide an interface between the devices and the system, so that it becomes easy to use this devices.
The operating system provide coordination between all the peripheral devices, instead of they arev quite different.
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78. Types of Operating Systems
Real-time operating system
RTOS are used to control machinery, scientific instruments and industrial systems.
Real time systems which were originally used to control autonomous systems such as satellites and robots
Very fast small OS
Built into a device
Respond quickly to user input
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79. Single user/Single tasking OS
One user works on the system
Performs one task at a time
MS-DOS and Palm OS
Take up little space on disk
Run on inexpensive computers
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80. Single Tasking
Operating System cannot be able to take control back from the running process/task/application
In case if a process call an I/O Instruction then Processor must wait for I/O instruction to complete before preceding
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81. Example of Single User, Single Task
The Palm OS for Palm handheld computers is a good example of a modern single-user, single-task operating system.
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82. Single user/Multitasking OS
User performs many tasks at once
Most common form of OS
Windows XP and OS X
Require expensive computers
Tend to be complex
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83. Multitasking
Operating System can take control back from the running process and can give it to other.
When one job needs to wait for I/O, the processor can switch to the other job
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84. Example of Single User, multi Tasking
Microsoft's Windows and Apple's MacOSplatforms are both examples of OS that will let a single user have several programs in operation at the same time.
For example, it's entirely possible for a Windows user to be writing a note in a word processor while downloading a file from the Internet while printing the text of an message.
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85. Multi user/Multitasking OS
Many users connect to one computer
Each user has a unique session
UNIX, Linux, and VMS
Maintenance can be easy
Requires a powerful computer
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86. Multi user/Multi tasking OS
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87. Examples of Multi-user
Unix, VMS and mainframe operating systems, are examples of multi-user operating systems.
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88. BATCH OS
Some computer systems only did one thing at a time. They had a list of instructions to carry out and these would be carried out one after the other. This is called a serial system. The mechanics of development and preparation of programs in such environments are quite slow.
Batch operating system is one where programs and data are collected together in a batch before processing starts. A job is predefined sequence of commands, programs and data that are combined into a single unit called job
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89. Figure below shows the memory layout for a simple batch system.
Memory is usually divided into two areas: Operating system and user program area.
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90. Advantages of Batch System:
1. Move much of the work of the operator to the computer.
2. Increased performance since it was possible for job to start as soon as the previous job finished.
Disadvantages of Bach System:
1. Turn around time can be large from user standpoint.
2. Difficult to debug program.
3.A job could enter an infinite loop.
4.A job could corrupt the monitor, thus affecting pending jobs.
5.Due to lack of protection scheme, one batch job can affect pending jobs.
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91. MULTIPROGRAMMING OS
When two or more programs are in memory at the same time, sharing the processor is referred to the multiprogramming operating system.
Multiprogramming assumes a single processor that is being shared. It increases CPU utilization by organizing jobs so that the CPU always has one to execute.
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92. Figure below shows the memory layout for a multiprogramming system.
( Memory layout for a multiprogramming OS)
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93. 1.CPU scheduling is required.
Advantages
1.High CPU utilization.
2. It appears that many programs are allotted CPU almost simultaneously.
Disadvantages
1.CPU scheduling is required.
2.To accommodate many jobs in memory, memory management is required.
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94. DESKTOP OS
During the late 1970, computers had faster CPU, thus creating an even greater disparity between their rapid processing speed and slower I/O access time
Multiprogramming schemes to increase CPU use were limited by the physical capacity of the main memory, which was a limited resource and very expensive. These system includes PC running MS window and the Apple Macintosh.
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95. MS-DOS is an example of a microcomputer operating system.
The most powerful microcomputers used by commercial; educational, government enterprises. Hardware cost for microcomputers are sufficiently low that a single user (individuals) have sole use of a computer. Networking capability has been integrated into almost every system.
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96. TIME SHARING OS
Time sharing system supports interactive users. Time sharing is also called multitasking. It is logical extension of multiprogramming.
Time sharing system uses CPU scheduling and multiprogramming to provide an economical interactive system of two or more users.
In time sharing, each user is given a time-slice for executing his job in round-robin fashion. Job continues until the time-slice ends.
Time sharing systems are more complex than multiprogramming operating system.
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97. MICROKERNEL OS
A microkernel is very small core of OS that allow easy portability of OS across different vendors computers.
It is predicted that all future OS will be built around a microkernel.
The microkernel approach replaces the layered approach of UNIX by a horizontal organization.
Fig shows the organization of microkernel called chorus developed in France.
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98. Chorus microkernel OS organization
Unix Process
Unix Procsee
Unix Process
User Space
Process
mgr
Disk Driver
File Mgr
System Space
Inter process communication
Real time executive
Memory manager
Chorus nucleus
Machine dependent supervisor
Fig. Chorus microkernel OS organization
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99. Unix OS
Unix is multiuser,time sharing OS which was written in 1973 by Ritchie and Thomson at Bell Telephone Laboratories USA.
Features of UNIX OS:-
Unix is writen in C, a high level language.
The interface provided to user is simple and powerful.
The file system used by UNIX is hierarchical which allows efficient implementation and easy maintenance.
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100. UNIX is multiuser,time sharing,multiprogramming OS.
UNIX supports scripting language called shell.
UNIX can support any programming language that has a compiler or an interpreter.
Fig shows the layers of UNIX OS
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101. H/W
For diagram refer book
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102. A set of program written for the computer is called software.
In computer science,computer software is nothing but all computer programs.
To perform any task on computer, the programmer has to write a set of instruction.
This sequence of instruction given to the computer is called a program.
A set of program written for the computer is called software.
Software is a program that enables a computer to perform a specific task, as opposed to the physical components of the system.
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103. SOFTWARE Software may be classified into 2 types:-
Application software
System software
application software :-
It is the set of programms necessary to carry out the operation for the specified application.
System software:-
They are general programs written for the system which provide the environment to facilitate the writing of application software.
Ex. Assembler, Compiler, Loader, Linker etc. ;
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104. System Control Software System Support Software
System Software
System Control Software
System Support Software
System Development Software
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105. System Control Software:
System Control programs control the execution of programs, manage the storage and processing resources of the computer, and perform other management and monitoring functions. The most important of these program is the operating system & DBMS(Data Base Management System).
Operating system: An operating system is a program that acts as an intermediate between the user and computer hardware.
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106. System Development Software :-
Language Processor
A Compiler
B Assembler
C Interpreter
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107. System Support Software :-
Utility Software
Disk defragmenters/Disk management tools
Virus scanners/Antivirus
Compression
File Management tools
Encryption
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108. Current Storage Format
CD’s
Consist of pits and lands stamped out in a spiral pattern on the disc.
A laser then reads the pits and lands.
The change from a pit to a land or a land to a pit indicates a one while no change indicates a zero.
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109. Current Media Format Cont.
CD-RW’s
Consist of a metal phase change alloy which when heated can be to change to reflectivity
CD-R’s
Consist of a dye that is applied to the disc.
When a writing laser is shined it changes the reflectivity.
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110. Current Media Format Cont.
DVD’s
Also contain pits and lands.
Are more highly compact than a CD.
Special laser is needed to read them.
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111. Blu-ray Technology Name
Derived from the blue-violet laser used to read and write data.
Developed by the Blu-ray Disc Association with more than 180 members.
Dell
Sony LG
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112. Blu-ray Technology Cont.
Data capacity
Because Blu-ray uses a blue laser(405 nanometers) instead of a red laser(650 nanometers) this allows the data tracks on the disc to be very compact.
This allows for more than twice as small pits as on a DVD.
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113. Blu-ray Technology Cont.
Data Capacity Cont.
Because of the greatly compact data Blu-ray can hold almost 5 times more data than a single layer DVD. Close to 25 GB!
Just like a DVD Blu-ray can also be recorded in Dual-Layer format. This allows the disk to hold up to 50 GB!!
Because the polycarbonate layer of the Blu-ray disc is so much larger than a DVD because the recording layer is so much smaller it can have even more than two layers.
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114. Blu-ray Technology Cont.
Writing Data
Blu-ray uses a combination of two lenses to greatly shrink the laser to read the data.
This also allows for higher data rate transfer close to 36 mbps.
It could record 25 GB of data in an hour an a half.
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125. Sunil Kumar Sahu,Lecturer RCET

126. HD DVD vs Blu-ray Both formats use blue lasers rather than red.
Both have the same options for video and audio compression.
Blu-ray offers significantly more storage space GB on a dual-layer disc versus HD-DVD's 30 GB.
The DVD Forum, which creates DVD standards, has approved HD-DVD and has not approved Blu-ray.
HD-DVD is less expensive than Blu-ray.
HD-DVDs can be produced on existing equipment, and Blu-ray discs can't.
HD-DVD players are selling for $499 (Toshiba HD-A1) to $799 (HD-XA1), and Blu-ray players are selling for around $1,000 (Samsung DB-P1000).
HD-DVD players hit the market on April 18, 2006, two months before the first Blu-ray player hit the U.S. market in June, 2006.
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127. HD DVD vs Blu-ray Cont.
Current supporters of HD-DVD include Toshiba, NEC, Sanyo, and Microsoft, in addition to New Line Cinema, Paramount, Universal, Time-Warner, and the official approval of the DVD Forum.
Current supporters for Blu-Ray includes PC makers Apple, Dell, Hewlett-Packard, and Sony, and electronics giants Hitachi, LG, Mitsubishi Electric, Matsushita/Panasonic, Pioneer, Philips, Samsung, Sharp, TDK, and Thomson. Add to this the support by movie studios such as Columbia TriStar, Sony Pictures and MGM (all three owned by Sony), 20th Century Fox, Lions Gate Entertainment, and Disney, as well as video game makers Electronic Arts and Vivendi Universal Games, and the bastion of support for Blu-Ray looks formidable indeed
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128. Hard Drives
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129. The Hard Drive
Hard drives are composed of individual disks or platters
The platters are made up of aluminum and coated with a magnetic medium
Two tiny read/write heads service each platter
Discussion Point
Hard drive housing
All moving components of the hard drive (platters, actuator arm, and read/write heads) are permanently sealed inside the housing to prevent contamination by minute particles. Even the tiniest speck of dust can destroy a hard drive and all the data it contains. Drives are assembled by the manufacturer in clean rooms.
Never open the case of a hard drive unless the drive is absolutely dead and/or totally unrecoverable, and you are just bored or curious.
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130. The Hard Drive
The closer the read/write heads are to the platter, the more densely the data can be packed on to the drive
Hard drives use a tiny, heavily filtered aperture to equalize the air pressure between the exterior and interior of the hard drive
Platters spin between 3500 and 10,000 rounds per minute (RPM)
Tech Tip
Fluid bearings
Currently, almost all hard drives use a motor located in the center spindle supporting the drive platters. Tiny ball bearings support the spindle motor, and as disk technology has advanced, these ball bearings have become the limiting factor in the three critical design criteria for hard drives: rotational speed, storage capacity, and noise levels. The higher the rotational speed of a drive, the more the metal-on-metal contact creates heat and lubricant problems that impact the lifespan of the bearings. However precisely machined, ball bearings are not perfectly round. The measurement of how much they wobble (and thus how much the drive platters wobble), called runout, is now the limiting factor on how densely you can pack information together on a disk drive. The technological fix? Fluid bearings. A fluid bearing is basically a small amount of lubricant trapped in a carefully machined housing. The use of fluid in place of metal balls means there’s no contact between metal surfaces to generate heat and wear, and no mechanical vibration, so fluid bearings can support higher rotational speeds. The runout of a fluid bearing is about one-tenth of that of the best ball bearing, increasing potential information density significantly. The absence of a mechanical connection between moving parts also dramatically reduces noise levels, and the fluid itself acts to dampen the sound further. Finally, liquid bearings provide better shock resistance than ball bearings.
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131. Types of Hard Disk Drives
ATA is the current standard, it uses regular molex power connectors and IDE cables. SATA is a newer product (also SATA2 is already in development) - it is faster than ATA and uses different cables - much thinner and neater. Also take into consideration the RPM of the drive, 5400 is a bit slow, 7200 is good, 10,000 is fast but can be quite noisy. Servers generally use 10k rpm SCSI hard drives, but SCSI is unusual in home computers. Most motherboards only have IDE connections and so can only take ATA, you would need a new motherboard for SATA hard drives. The capacity that you need is simply dependant on how much you plan on saving to your hard-drive. Usually from 40GB upwards
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132. Hard Drive
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133. Data Encoding
Hard drives store data in tiny magnetic fields called fluxes
The flux switches back and forth through a process called flux reversal
Hard drives read these flux reversals at a very high speed when accessing or writing data
Fluxes in one direction are read as 0 and the other direction as 1

134. Data Encoding Run length limited (RLL)
Encoding methods used by hard drives are
Run length limited (RLL)
Data is stored using “runs” that are unique patterns of ones and zeroes
Can have runs of about seven fluxes
Partial Response Maximum Likelihood (PRML)
Uses a powerful, intelligent circuitry to analyze each flux reversal
Can have runs of about 16 to 20 fluxes
Significantly increased capacity (up to 1 TB)
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135. Arm Movement in the Hard Drive
The stepper motor technology and the voice coil technology are used for moving the actuator arm
Moves the arms in fixed increments or steps
Only seen in floppies today
The voice coil technology uses a permanent magnet surrounding the coil on the actuator arm to move the arm
Automatically parks drive over non-data area when power removed
“Parking” a drive is meaningless in today’s PCs.
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136. Geometry
Geometry is used to determine the location of the data on the hard drive
CHS (cylinders, heads, sectors)
Used to be critical to know geometry
Had to enter into CMOS manually
Today, geometry stored on hard drive
BIOS can query hard drive for geometry data
Discussion Point
The geometry we need to know: cylinders, heads, and sectors
Back in the old days, we always had to enter this information into the CMOS manually for the BIOS to know how to communicate with the drive. Today, this information is automatically stored on the drive and detected by the BIOS. However, since we routinely see older systems in our work, we still need to know this information. If this geometry is not marked on the drive housing, as is the case with many older drives, it is usually available at the drive manufacturer’s Web site. I usually write the geometry information and the jumper information on the drive housing with a marker so I won’t have to look it up again.
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137. Heads Number of read/write heads used by the drive to store data
Two heads per platter (top and bottom)
Most hard drives have an extra head or two for their own usage, so the number may not be even
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138. Basic components of a hard drive
Disk platters
Read/write heads
Head actuator mechanisms
Spindle motor
Logic board
Cables & connectors
Configuration items (such as jumpers & switches)
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139. Hard Disk Platters
Hard disks have been a number of different form factors over the years
3 1/2 inch drives are the most popular for desktop & some portables
Max number of platters in a 3 1/2 inch drive is 11
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140. Hard Disk Platters
No matter what type of platter is used, the platters are covered with a thin layer of magnetically retentive substance (called the medium) on which magnetic information is stored.
Oxide media
Thin-film media
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141. Read/Write Heads
A hard disk has one read/write head for each side of the platter
The heads are connected on a single movement mechanism
They move in unison
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142. Head Actuator Mechanism
A drive using a stepper motor is much less reliable than one using a voice coil
Floppy drives use a stepper motor to position their heads
Accuracy of the stepper is suited to a floppy drive, because track densities usually lower
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143. Spindle motor Motor that spins the platters
Connected directly to the drive
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144. Logic Boards Mounted on the hard drive
Contain electronics that control the drive’s spindle & head actuator systems & present the data to the controller
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145. Cables & Connectors
Sever connectors for interfacing to the computer, receiving power & sometimes grounding to the system chassis
Three types
Interface connectors
Power connectors
Option ground connector (green wire)
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146. Speed of the Drive Average Seek time
Measured in milliseconds - average amount of time it takes to move the heads from one cylinder to another cylinder a random distance
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