## Wednesday, July 1, 2020

### ARITHMETIC CALCULATION IN COMPUTERS

ARITHMETIC OPERATION AND CONVERSION DONE BY COMPUTER

As we have seen in previous post that arithmetic computation is an important thing in calculation, if a person doesn’t know arithmetic computations,  he will be doomed to be in trouble during calculations that happens  in everyday life.  So it is necessary to learn arithmetic computation.  So in this post I am going to take one step further.  I am going to write about octal and hexadecimal numbers.

Now let us discuss some arithmetic conversion.  Let us see what is octal and hexadecimal numbers used by digital computer.

The conversion from and to binary, octal and hexadecimal plays an important part in digital computers.  Since 23 = 8 and 24 = 16 each octal digit corresponds to three binary digits and each four binary digit corresponds to one hexadecimal digit.

The conversion of from binary to octal is easily accomplished by partitioning the binary into group of three digit each, starting from binary point and preceding to the left or to the right.

The corresponding octal digit is then assigned to each group.  The following  example illustrates the procedure.

10 110 001 101 011 .  111 100 000 110   = (26153.406)2
2     6     1     5      3        7      4       0     6

Conversion from binary to hexadecimal is similar,  except that the binary number is divided into group of four digits:

10 1100 0110 1011 .  1111 0010    =  (2C6B.F2)16
2     C       6       B            F        2

The corresponding hexadecimal (or octal) digit for each group of binary digits is easily remembered after studying the values.

Conversion from octal or hexadecimal to binary is done by procedure reverse to the above.  Each octal digit  is converted to three bit binary equivalent .  Similarly, each hexadecimal digit  is converted to its four-digit binary equivalent.

Binary numbers are difficult to work with because they require three or four times as many digits as their decimal equivalent .  For example, the binary number 111111111111 is equivalent to decimal number  4095.  However, digital computers use binary numbers and its sometimes necessary for human user to communicate directly to with the machine by means of binary numbers.

One scheme that retains binary  system  in the computer but reduces the number of digits human must consider utilizes the relationship between  binary number system and octal and hexadecimal system.  By this method, the human thinks of the number of octal and hexadecimal  numbers  and performs required conversion by inspection when direct communication by the machine is necessary.  Thus the binary numbers 111111111111 is 12 digit and is expressed in octal as 7777 (four digits) and while it is expressed in hexadecimal as FFF (3 digits).

During communication between people (about binary numbers in the computer), the octal or hexadecimal representation is more desirable because it can be represented in third or quarter of number of digits required for equivalent binary number.

When the human communicates with the machine (through console switches or indicator lights or by means of programs written in machine language),  the conversion from octal or hexadecimal  to binary and vice versa is done by inspection by the human user.

## Sunday, June 14, 2020

### MONITORS: A COMPUTER PART

Folks today i am going to say something about an output device called monitor.  As maximum people know about monitors so i am going to write few things about monitor much of the information you know but i am going to say some few words hence please be with me.

Monitor is a primary output device.  It displays all current process application and data i.e. Running inside a computer system.  A standard monitor uses an analog vga interface, which plugs into a tp15 vga connector to a mother board.  There are two types of monitor technology available to the market.

CATHODE RAY TUBE (CRT MONITOR)

This monitor is fading in popularity but still in widespread use with older computer systems.  It is analog standard monitor a crt uses a picture tube that was used in older tube based tv sets.

The narrow end of the picture tube contains an electron gun it emits 3 electron beams one each for red, green and blue light.  The front end of the picture tube is coated with phosphorous.  When the elecron hit the phosphorous coating it starts to glow.

Just before the phosphorous coating a metal plate called a shadow mask uses one of the three technologies phosphor triad, an aperture grill, a slotted mask.
Crt monitors are bulky, takes more desk space, consumes more power and emits more heat.  Crt monitors were available from 15 inch to 19 inch size.  It uses vga connector to attach with a cpu.

LCD AND LED SCREENS

The most popular monitor in todays market is led monitor surpassed lcd monitors.  Because it gives better color quality, wide viewing angle and consumes less power.  It uses liquid crystal cells to polarize the light.  Lcd uses fluorescent lamp and led monitor uses led lamp for back lighting.  This display uses an array of transistors to control each cell variation are the colour bit response time and the refresh rate.
This monitor comes with two types of transistor technology (1) passive matrix (2) active matrix.
Now i will discuss about passive matrix so lets be.
PASSIVE MATRIX
A passive matrix display does not have a dedicated transistor for each pixel or sub pixel, bit instead of a matrix of conductive traces.  In simplified terms for a single pixel, when the display is instructed  to change the crystal line alignment for a particular pixel and sends a signal  accross the x and y coordinate traces that intersect at that pixel, thus turning it on.  A 1366 * 768 resolution monitor contains 1366 transistors at that horizontal edge and 768 in vertical edge. The viewing uncle is a most unconsiderable issue of a passive matrix display.  The picture quality is muddy because the conductive traces sometimes affects the neighbouring pixels of a target pixel. The one advantage of passive matrix is it consumes less power comparing to active matrix display.

DUAL SCAN DISPLAY
A dual scan is a  variation of the passive metric display.  The classic passive matrix screen is split in half to implement a dual scan display.  Each half of the display is refreshed separably leading to increased quality.  Although dual scan improves the quality of refresh rate but it cannot rival the quality produced by active matrix.

ACTIVE MATRIX

This screen is made of several independent lcd or led pixels.   A transistor at each pixel location, when switched among various levels activates two opposing electrodes that align the pixels crystal two opposing electrodes that align the pixels crystals and alter the passage of light at that location two produce millions of colour shades.

This type of display is very crisp and easy to look at from any angle.  It doesn’t require a scan refreshing to maintain an image.  Because transistors conduct current only in one direction and the pixels acts like a capacitor by holding its charge until it is refreshed.

Higher refresh rate results in better video a gaining performance not for still image.  The major disadvantage of active matrix screen but it requires more power to operate all transistors.  Even if the backlight is turned of the screen can still consume power at an alarming rate.  Another problem with active matrix is light bleed.

## Thursday, June 11, 2020

### SUMMARY OF MEMORY

RAM PROPERTIES
Friends in the last post i tried to explain the different types of ram as well as given the details of its similarities now i am going to show you how the properties of ram can be judged .

SO LET US BEGIN.

SINGLE SIDED VS DOUBLE SIDED
DIMMS or DUAL INLINE MEMORY MODULE whatever you call are often referred to as single chip or double sided to describe whether the chips are located on one or both of the modules printed circuit board .

However these terms may cause confusion or distract you from the topic, as the physical layout of the chips does not necessarily relate to how they are logically organized or accessed in whatever terms you are told.

ERROR CORECTING CODE MEMORY (ECC MEMORY)
An ERROR CORRECTING CODE (or ECC) whatever general public says could be a kind of computer data storage which will detect and proper the more common types of internal data corruption in simple words with firmness and boldness.

Most computers or workstations use ECC where data corruption
of knowledge or misspelt or mislead data can't be tolerated under any circumstances or in any mislead cannot be tolerated during this way like for scientific or financial computing in firm terms.

Error correcting code (ECC) memory
is commonly seen in high end motherboards or firms that use ECC memory that provide important services or software functions. Unlike normal parity memory, ECC memory can find and fix errors, i'm saying these items in generalized manner.ECC memory generally costs more, so usually see motherboard designed for ECC memory when there as a specific need .

ECC memory maintains a memory system effectively free from single bit errors, usually it does in this way to prevent redundancy.  The data i.e. Read from each word is always the same as the data that had been written to it, even if the single bit is actually  stored or more in some cases has been to the wrong state.

The ECC memory is employed where the info must be very accurate and also the memory is required to possess a correcting capability.

It adds cost to the memory module and
employed in server level computers where the info accuracy is incredibly important some non ECC memory with parity support allows errors to be detected but not corrected otherwise errors which will occur don't seem to be detected now which is why it's on the demand in markets.

Now we are
visiting speak about memory modules. So let s begin

SINGLE INLINE MEMORY MODULE

A SIMM or
one inline memory module may be a form of memory module containing random access memory employed in computers from the first 1980 s to the late 1990 s and it had been in pretty much demand.

It differ from dual inline memory module
the foremost predominant type of memory module today therein the contacts on a SIMM or redundant on each side of the module.

DUAL INLINE MEMORY MODULE

A DIMM or dual inline memory module comprises a series of dynamic random access memory integrated circuits. These modules are printed on
computer circuit boards and designed to be used in personal computers, workstations, and servers.
DIMMS began
to exchange SIMMs because the predominant form of memory module because the intel p5 based pentium processors to achieve market share. While the contact on SIMMs on each side are redundants , DIMMS have separate electrical contacts on each sides of the module.

Another different is that standard SIMMs have 32 bit data path, while standard DIMMS have 64 bit data path.

## Sunday, June 7, 2020

### PROCESSOR AND HYPER THREADING A SHORT SUMMARY

Friends in the last post i tried to say something about computer science and mathematics relationship.  Now i am going to say something about processor and hyperthreading.  So let’s get started.

The Physical Component By Which A Computer Is Mde Which We Can See, Touch And Feel Is Called Computer Hardware Example Ram, Motherboard.
·         INPUT DEVICE  : These hardware are used to input any data, instruction on command insidea computer device.  example keyboard mo9use scanner microphone, webcam etc
·         OUTPUT DEVICE:  these hardware are used to get any output from a computer system.  example: monitor, printer, speaker.
·         CENTRAL PROCESSIG UNIT (CPU): This Device Proceses All Instruction Given By A User, And It Also Other Haqrdwqaar Peripherals Example  :Microprocessor
·         MOTHERBOARD: It is the main electric circuit board which is made by a pcb(printed circuit board).  It hods all hardware components and provide interface to those component by which they can communicate with each other.
·         MEMORY: These hardware are used to storedata temporarily on permanent.  these are two types
o   PRIMARY MEMORY:- These Memories Are Direclty Accessed By A System Cpuit Does Not Need Any Third Controller To Occur This Memory Example :- Ram , Rom
o   SECONDARY MEMORY:- A cpu needs additional computer to access this memory.  They are basically storage device. Example:- hard disc, cd-dvd, pendrive, sd cards etc.
·         POWER SUPPLY UNIT (PSU):-  This Unit Convert Alternating Current To Direct Current And Provides A Regulated Popwer Supply To All Hardware Peripherals Example :- Switch Mode Power Supply.

All the above is written by me is to acknowledge you about the primary technology of the computer peripherals.  Now i am going to tell you about the cpu and its secondary technology.

SINGLE CORE VS MULTI CORE
A cpu contains single or multiple processsing chips.  These chips are made by silicon.  A chip takes three hundrede steps to be manufacture. A processing containing single chip is known as single core processor .

In dual core it contains two chips that means it have two processor in a package.  In quadcore it contains four chip and show on more numbers o chips gives better performance and reduces processing delay.

It is a feature of certain intel processor that makes one physical cpu and appears two logical cpu.  It uses additional registers two overlap two instruction which achieve an appropriate thirty percent gain in performance.

Multi threaded applications take advantage of hyperthreading .  But it cannot rival with the performace achieved by a true dual core processor it was introduced by intelwiht their prentium four processor and reffered as “ht” technology.

This technology is supported by syistem software to take advantage.  Most of the todays operating system such as windows and linux aree capable of dividing their workload among multiple processors. This is called symmetric multi processing (smp).

## Thursday, April 30, 2020

### MATHEMATICS AND COMPUTER SCIENCE RELATIONSHIP

MATHEMATICS AND COMPUTER SCIENCE RELATIONSHIP.

In today’s world mathematics is a must learned subject .  In all the inventions and discovery , the main reason for their success of the practical’s are due to mathematics.  So in order to make a career in today’s world require mathematics.

But this Is blog of computers science and information technology, then why should we read mathematics so it requires mathematics to understand the reason behind such technology.  So I am going to write something about mathematics for its uses and technology in the computer world.
One of the main aims of logic is to provide rules by which one can determine whether any particular argument or reasoning is valid (correct)
Logic is concerned with all kinds of reasoning whether they be legal arguments or mathematical proofs or conclusions in a scientific theory based upon a set of hypothesis.  Because of the diversity of their application these rules are called rules of inference, must be stated in general terms and must be independent of any particular language used in the arguments.

More precisely, in logic we are concerned with the forms of argument rather than arguments themselves.  Like any other theory in science the theory of inference is formulated in such a way that we should be able to decide about the validity of an argument by following the rues mechanically and independently of our own feelings about the argument.

Of course to proceed in this manner requires that the rules mechanically and independently of our own feelings about the argument.  Of course to proceed in this manner requires that the rules be stated unambiguously.

Any collection of rules or any theory needs a language in which these rules or theory can be stated.  Natural languages are not always precise enough.  They are also ambiguous and as such are not suitable for this purpose.

It is therefore necessary first to develop a formal language called the object language.  A formal language is one in which the syntax is well defined.  In fact, every scientific discipline develops its own object language which consists of certain well-defined terms and well specified uses of these terms.

The only difference between logic and other disciplined is that in other disciplines we are concerned with the use of the object language while in logic we are as interested in  analyzing of an object language without considering its use in the theory of inference.

In order to avoid ambiguity we use symbols which have been clearly defined in the object languages.  An additional reason to use symbols is that they are easy to write and manipulate.  Because of use this symbols the logic that we shall study is also called symbolic logic, Our study of the object language requires the use of another language.

For this purpose we can choose any of the natural languages.  In this case our choice is English and so the statements about the object language will be made in English.  This natural language (English) will them be called or meta language.  Certain inherent difficulties in this procedure could be anticipated.  Because we wish to study a precise language while using another language which is not so precise.

## Friday, April 3, 2020

### INTERNET A GLIMPSE

We live in a world where every field requires use of computers.  But computers need data to process the output.  This data can be gathered with the help of internet.   The internet uses World Wide Web to gather data.  So the user must know the basics of the internet.  So I am going to acknowledge the basic parts where and how the computer uses internet.  I am going to discuss about OSI layers.

Osi means open system interconnect  and was invented by ISO (INTERNATIONAL SYSTEM OF ORGANIZATION) which is an institution who manages giving standardization of the products to be manufactured.  It was invented by iso in 1984.  The use of iso in networking terms is to provide networking standardization of frame work  for implementing network protocols to be used in seven layers.

The seven layers breaks down the process of communication into smaller and easier to handle independent categories.  Before osi different networking vendors couldn’t communicate with each other.  After iso now different vendors have the ability to converse with each other.  Hence it is called platform independence

Now I will show you computers communicate with each other through the use of seven layers.  Now lets get started

We will start from the layer 1 of seven layers and continue till the last layer.  They are as under
1.       Application layers
2.       Presentation layers
3.       Session layers
4.       Transport layers
5.       Network layers
7.       Physical layers

1.APPLICATION LAYER
Application layers helps us and is responsible to work with application layer softwares by which we use or access a network .  Application softwares are

APPLICATION SOFTWARES:

APPLICATION PROTOCOLS EXAMPLE
HTTP, FTP, SMTP, POP3, NTP etc.

2.PRESENTATION LAYER
This layer works with file types means compression and decompression of file types as well as change one file type to other file types.  It is also used data encryption and decryption too.

PICTURE  : .jpeg, .bmp, .png, .gif
AUDIO    : .mp3, .wav, .ogg, .flac, .amv
VIDEO             : .MP4, .MKV, .AVI, .3GP, .MPEG
DOCUMENT:  .DOCX, .XLSX, .PPT, .PDF, .TXT, .RTF, .HTML

3.SESSION LAYER
Session layer is responsible for creating, managing and terminating a session, it also works with mode of communications.

4.TRANSPORT LAYER
The transport layer is responsible for  what the actual mechanism of creating as well as terminating  session where it can provide both reliable and unreliable data delivery.  It is also responsible for error correction remember error correction is defined in this layer but error detection is done in network layer.

This layer has 5 main function
1.       It tears down and sets up an session connection between two components.
2.       It can provide reliable as well as unreliable data delivery
3.       It segments or crops down data in smaller and manageable sizes.
4.       It multiplexes connection allowing multiple application to send and receive data simultaneously on the same networking device
5.       It also provides flow control and avoids congestion

Transport layer has two types of protocols.

Transmission control protocol
Transmission control protocol is a connection oriented reliable protocol because it gives acknowledgement.  It is slow protocol the connection is eastablished by 3 way :-handshaking process.

Now I am going to tell you about port number which is used in Transmission control protocol.

Port Number
It is also known as transport layer or layer 4 address.  This number is used for protocol identification.  It is a 16bit address maximum port number will be 216  = 65536.  This number is controlled by internet assigned number authority  (IANA).

IANA has grouped this number in 3 groups
This address are registered and controlled by IANA.  Range is  (0  - 1023).  To view this address go to RUN- %Systemroot% \system32 \drivers\etc\services. Open the file in  notepad.

This addresses are registered and not controlled by IANA. Range is (1024-49151).

This addresses neither register nor controlled by IANA.  It is automatically used by desktop                             computers.  A range (49152-65535).

5. NETWORK LAYER
This layer defines the logical address of networking devices.  It is also responsible for finding paths based on the network numbers of logical addresses to reach destination components.  It connects different data link layer network types together such as serial, Ethernet, token ring etc.
This layer has two types of protocols
1.       ROUTED PROTOCOLS
This protocol defines the source and destination address of data packet (where are the data packets are and where it will go)  e.g. – Internet Protocol, Internet Packet Exchange (IPX), Sequenced Packet Exchange (SPX),  APPLE TALK.
2.         ROUTING PROTOCOLS
This protocol defines how the data packet will converge from one network to another.  It defines the best path also known as shortest path to reach destination on network
i.                     Routing information protocol
ii.                   Open Shortest Path First
iii.                  Enchanced Interior Gateway Routing Protocol
iv.                 Border Gateway Protocol

This layer is responsible for defining the format for layer two frame as well as the mechanics of how devices communicate with each other over the physical layer.  The data link layer is responsible for the following
2.       Defining the physical or hardware topology for connection.
3.       Defining how the network layer Protocol is encapsulated in the data link layer frame.
4.       Providing both connectionless and connection oriented services.

7.                 PHYSICAL LAYER
The bottom most layer of OSI model in the physical layer.  The physical layer is responsible for the physical mechanics of a network connection, which includes the following
1. The type of interfaced used in networking device
2.  The type of cable used in the networking devices.
3.  The connector used in each end of the cable.
4.  The pin pattern used for each of the connections on the cable.
5.  The encoding of the messages on the symbol by converting binary digits to a physical                            representation based on the media type such as electrical copper, light for fibre and radio for wireless.