Multiprocessing Computer

Multiprocessing Computer
From Wikipedia

Some computers may divide their work between one or more separate CPUs, creating a multiprocessing configuration. Traditionally, this technique was utilized only in large and powerful computers such as supercomputers, mainframe computers and servers. However, multiprocessor and multi-core (multiple CPUs on a single integrated circuit) personal and laptop computers have become widely available and are beginning to see increased usage in lower-end markets as a result.

Supercomputers in particular often have highly unique architectures that differ significantly from the basic stored-program architecture and from general purpose computers. They often feature thousands of CPUs, customized high-speed interconnects, and specialized computing hardware. Such designs tend to be useful only for specialized tasks due to the large scale of program organization required to successfully utilize most of the available resources at once. Supercomputers usually see usage in large-scale simulation, graphics rendering, and cryptography applications, as well as with other so-called "embarrassingly parallel" tasks.

Computer Multitasking

Computer Multitasking
From Wikipedia

While a computer may be viewed as running one gigantic program stored in its main memory, in some systems it is necessary to give the appearance of running several programs simultaneously. This is achieved by multitasking i.e. having the computer switch rapidly between running each program in turn.

One means by which this is done is with a special signal called an interrupt which can periodically cause the computer to stop executing instructions where it was and do something else instead. By remembering where it was executing prior to the interrupt, the computer can return to that task later. If several programs are running "at the same time", then the interrupt generator might be causing several hundred interrupts per second, causing a program switch each time. Since modern computers typically execute instructions several orders of magnitude faster than human perception, it may appear that many programs are running at the same time even though only one is ever executing in any given instant. This method of multitasking is sometimes termed "time-sharing" since each program is allocated a "slice" of time in turn.

Before the era of cheap computers, the principle use for multitasking was to allow many people to share the same computer.Seemingly, multitasking would cause a computer that is switching between several programs to run more slowly - in direct proportion to the number of programs it is running. However, most programs spend much of their time waiting for slow input/output devices to complete their tasks. If a program is waiting for the user to click on the mouse or press a key on the keyboard, then it will not take a "time slice" until the event it is waiting for has occurred. This frees up time for other programs to execute so that many programs may be run at the same time without unacceptable speed loss.

Computer Brands

Computer Brands
By Dan Preston

So you’ve finally decided its time for a change. No matter what advice you follow that old workhorse of a desktop computer you have has outlived its usefulness with slow loading applications and a continuous rise in operation noise.

Searching for that Perfect

Computer can be about as much fun as purchasing a new car and about as frustrating also when sorting through the various brands while trying to decide which “bells and whistles” best fit your needs. Besides all that trying to return something that is so large can be both inconvenient and very difficult to do. So making the right decision the FIRST time is the wise path of choice.

For starters you’ll need to decide what you want to do with your computer. Are you into the video game scene or are you someone who likes to just surf the Internet and occasionally do some book keeping with simple word processing software?

If you’re into video games you’re going to want a machine that can handle the high level of graphics and superior sound quality. On the other hand if you’re not into all that high adrenalin stuff you can probably get by with a less expensive system. Although, if you want to stay on the safe side I would recommend going with something more “high-end” so you don’t have to spend another large chunk of change to upgrade the system you just bought.

There are two basic routes you can take when purchasing a new

computer.
1) Purchase a “Brand Name” Computer

2) Purchase a “Clone” Computer

A “BRAND-NAME” computer is one that is manufactured by a company that is recognizable by name.

Some Advantages/Disadvantages of “Brand-Name”

computers include:

Advantages:

Customer Support- If you are experiencing problems with your computer you will have the option to contact a representative of the company that you purchased the PC from to get help in solving your problem. Customer support is probably the best reason to buy a brand-name

computer.

Warranty- having a warranty is always nice since it acts as a type of security blanket for you. In case a part on your

computer should fail you should be able to get the item fixed at no charge just as long as the warranty has not expired.

Read and understand a company’s warranty policy BEFORE you purchase a computer from them.
This way you’ll have a good understanding of the procedures to follow in case a problem should arise.

Pre-installed Software- Many companies will include software packages that are all set up and ready to go for you on your

computer.

Although, a disadvantage of buying a brand-name

computer with software pre-installed is that you usually end up with more than fits your needs and usually just results with the wasting of space on your storage device.

Additional Support- Most brand-name

computer companies are also able to provide you with web sites that may provide you with current software updates, user manuals, or basic troubleshooting help.

Disadvantages

The use of Proprietary parts- the term Proprietary refers to products that are unique to an individual company and that company only.

So if a part was to malfunction on your computer after warranty and you needed to replace it you could not just go to your local

computer store and purchase any old part even if it was intended for the same function as the item that failed.

You would be forced to buy the exact same item that came out of the

computer or else the computer would more than likely cease to function correctly.

Having to buy proprietary parts usually involves the need to place an order which means you’ll have to wait for the part to arrive or you’ll have to send your

computer into the company or an authorized dealer of that company for repairs.

People with a home-based business would probably not be too happy with that situation at all. Integrated/On-board parts- In the computer world when you hear the word integrated or on-board it means that a particular part such as the modem or sound port where you plug in your speakers, is built-in or part of the computer main board (Also known as the Motherboard).

This means that if any of these items should fail, you can’t just remove them from the

computer and replace them with a new part. They are usually soldered directly to the main board and are stuck there.

Although, some computers do provide a way to disable a malfunctioning device, which will allow you to install your own store bought device to take the place of the broken part. From a computer technicians point of view this is not always easy to do. It just depends on what brand of computer you currently have. Meaning some are easier to work on than others.

A “CLONE” computer is a clone or a copy of its brand-name counterpart with the exception that instead of company specific or proprietary parts, the items used to make a clone

computer are from several different companies instead of only one.

Let’s say that if you were to go to a local company that builds “clone”

computers, and you tell them what you need, chances are they don’t use parts that are specific to only that type of computer like the brand-name computer companies do.

This is a good thing because it means that they will probably use components that are interchangeable with many different brands and are easy to come by if needed.
Some Advantages/Disadvantages of “Clone”

computers include:

Advantages:

Cost- compared to brand-name computers the clone will generally be easier on your pocket book when purchasing one with similar features as its brand-name counterpart.

This is most likely due to the money that is saved by not offering the high-end customer service. Although, that may not be the only reason for the lower prices.

Easily Accessible Replacement Parts- Since the clone

computer was built with parts that are not any one company specific, you can buy parts for the clone computer that can be used even if the brand is different from the one that was in the computer when you originally bought it.
NOTE: Before you buy any parts, it is necessary to make sure that the replacement parts are compatible with your particular computers system requirements.

Either consults the manual that should have come with your computer or get help from a knowledgeable friend or repairperson.

Disadvantages:

Warranties- unless you purchase a service plan you will typically not have as an attractive warranty as you would with a brand-name

computer company.

Whatever you do just make sure you understand how long the warranty is for and as to what kind of repairs the warranty covers before you make the purchase.

Customer Support- With brand-name computer companies you are usually provided with a 24-hour toll free number that you can call if you have questions or concerns with your

computer.

Clone

computers are more than likely not going to have a 24-hour help service, but rather you will be forced to only be able to call during regular business hours.

Also, it is more than likely that there will not be any one website that you can go to in order to find out information concerning troubleshooting questions you may have.

For service it may be necessary to take the

computer back to the store that you bought it at or you may have to do some research on the individual parts that went into the computer and visit the manufacturer’s website for troubleshooting tips.

Finally, if all else fails you can certainly take what you have learned from this article and being that you know what you need now, but don’t know where to go and get that “Perfect

Computer”, the best resource at your disposal are the very men and woman that work at your local electronics shop.It is their duty to help you get hold of that “Perfect Computer” that best fits your needs. All you need to do is tell them what you plan on using that computer for and they should be more than happy to help you from there.

Computer CPU

Computer CPU
From Wikipedia

Some computers may divide their work between one or more separate CPUs, creating a multiprocessing configuration. Traditionally, this technique was utilized only in large and powerful computers such as supercomputers, mainframe computers and servers. However, multiprocessor and multi-core (multiple CPUs on a single integrated circuit) personal and laptop computers have become widely available and are beginning to see increased usage in lower-end markets as a result.

Supercomputers in particular often have highly unique architectures that differ significantly from the basic stored-program architecture and from general purpose computers. They often feature thousands of CPUs, customized high-speed interconnects, and specialized computing hardware. Such designs tend to be useful only for specialized tasks due to the large scale of program organization required to successfully utilize most of the available resources at once. Supercomputers usually see usage in large-scale simulation, graphics rendering, and cryptography applications, as well as with other so-called "embarrassingly parallel" tasks.

Cheap Computers

Cheap Computers
From Wikipedia

While a computer may be viewed as running one gigantic program stored in its main memory, in some systems it is necessary to give the appearance of running several programs simultaneously. Having the computer switch rapidly between running each program in turn.

By remembering where it was executing prior to the interrupt, the computer can return to that task later. If several programs are running "at the same time", then the interrupt generator might be causing several hundred interrupts per second, causing a program switch each time. Since modern computers typically execute instructions several orders of magnitude faster than human perception, it may appear that many programs are running at the same time even though only one is ever executing in any given instant. This method of multitasking is sometimes termed "time-sharing" since each program is allocated a "slice" of time in turn.

Before the era of cheap computers, the principle use for multitasking was to allow many people to share the same computer.Seemingly, multitasking would cause a computer that is switching between several programs to run more slowly - in direct proportion to the number of programs it is running. However, most programs spend much of their time waiting for slow input/output devices to complete their tasks. This frees up time for other programs to execute so that many programs may be run at the same time without unacceptable speed loss.

Computer Technical Support

Computer Technical Support
By Dan Preston

There comes a time in a person’s life where no matter how much you fight it time takes its toll and we begin to slow down in how we perform our daily activities. However, in order to extend our youthful glow and energy levels it is important to eat right, exercise, and keep a positive outlook on life.

Now you may ask what has any of that got to do with “Secrets To A Healthy

Computer?”
Well, in a way we’re all just like a computer. If you neglect to take care of yourself you soon will cease to function properly and the many tasks that once were easy to do now take twice as long to accomplish and often require you to rest or “reboot” after a malfunction.

I can’t tell you what foods to eat or what exercises to perform because I am not a nutritionist. Although, with my experiences in the personal computer field I can share with you some tips of how to keep that rectangle box of circuitry that sits within sights range functioning at maximum performance as long as time will allow.

Some important steps to follow are….

Make certain that your computer is located in a well-ventilated area and that all air vents are unobstructed to prevent overheating and premature failure to any internal components.
Clean out the dust build-up at least every 6 months from the inside of the computer case including case vents, power supply vents, and all visible circuitry with a few cans of compressed air that can be purchased from any major

computer store or electronics outlet. This will help reduce the chances of overheating and circuitry damage.

Before cleaning just is certain to always unplug the

computer from the wall outlet and never physically contact the circuitry inside the computer case to prevent damage.

Be prepared for an unsuspected failure by always making backups of any important data that you do not and cannot afford to lose.

I personally keep updated backups of my

website and even store the disks at a remote location away from my every day use computers just in case a disaster were to occur and my main computers were destroyed resulting in the need for those lost files.

Purchase and install a well-known

anti-virus program that can be regularly updated with the latest virus definitions and ran during boot-up to help protect your computer from being the victim of an unwanted infestation.

Every few months or so run your computer’s “Scandisk” program followed by the “Defragmenter”

program to maximize the efficiency of your hard drive.

If you are not certain of how to use these utilities and being that the steps to execute these programs varies slightly from one operating system to the other it would be easiest to simply use the “Help” option that can be found by clicking on the START button found on your computers desktop.

The START menu will open up a drop-down-box that should display the “Help” option. By going here you can enter the keywords that deal with the answers to the subject you are searching for.
Run your computers “

Disk Cleanup” utility every other week or so. If set the “Disk Cleanup” utility will automatically empty the recycling bin and recover some wasted disk space by removing the Internet temporary files that seem to always accumulate.

Again, use the “Help” option if you are uncertain of how to perform this task.

Never smoke near a computer because the cooling fans will pull the smoke into the case where it can coat the inside parts of the computer with a residue which in turn can damage sensitive components.

Place the

computer case in an area where it will not be accidentally kicked or bumped to prevent the loosening of cables and damage to internal parts.

Invest in a high quality surge protector to provide your computer and monitor against voltage spikes or “surges” that can dramatically shorten the life of your system. Just like most items in a store, “You get what you pay for”. So don’t skimp out on this important device!

Its also not a bad idea to invest in a surge protector that includes what is called a “

Data Line Protector” which allows you to connect your telephone lines to and serves the same purpose for the telephone line to your modem just like the surge protector does for the electrical household current lines.

Finally, if you plan on being away from home for more that a few days at a time or if there is a thunderstorm brewing in your area it is a very wise decision to always unplug all electrical lines and modem telephone lines from your system. Even with a surge protector installed it is possible that such a large voltage spike such as one caused by a lightening strike could prove fatal to any

computer system.

If you follow these simple steps the outcome is a healthy computer that will stay by your side and treat you well which also results in a happier you.

Computer Input/Output

Computer Input/Output
From Wikipedia

I/O is the means by which a computer exchanges information with the outside world. Devices that provide input or output to the computer are called peripherals. On a typical personal computer, peripherals include input devices like the keyboard and mouse, and output devices such as the display and printer. Hard disk drives, floppy disk drives and optical disc drives serve as both input and output devices. Computer networking is another form of I/O.

Often, I/O devices are complex computers in their own right with their own CPU and memory. A graphics processing unit might contain fifty or more tiny computers that perform the calculations necessary to display 3D graphics. Modern desktop computers contain many smaller computers that assist the main CPU in performing I/O.

PC Video Conferencing

PC Video Conferencing
By Shakir A.

One of the best and the latest technologies in the area of video conferencing is

PC video conferencing. This is the most cost effective method of video conferencing as all one needs is a web cam and a microphone along with an Internet connection. Unlike other systems where an entire unit has to be set up such as video output devices and cameras the PC video conferencing, also known as desktop video conferencing, brings video conferencing right into your homes. IT experts have been working round the clock to develop the best PC video conferencing software all over the globe. Everyone seems to claim that they have the most advanced PC video conferencing software ever developed. However, you can be the best judge of their claims.

PC video conferencing software was Lunched a few years ago and is better known as P2P video-conferencing technology that integrates text chat, screen and document sharing and full session recording while remaining extremely easy and simple to use even for the people who are first timers to PC video conferencing. This Windows based software can be adapted to other operating systems such as Linux and Macs. Though PC video conferencing software is developed for few large and very prestigious corporations it is available for the large consumer market as well.

It is falsely believed by the man in the street that if PC video conferencing software doesn't strike home fast and get a footing in the domestic market or gets new some funding from the government you won't be able to buy PC video conferencing software for your own private use. But here is where they are all wrong. PC video conferencing software is available free for download on many sites on the Internet. PC video conferencing software is becoming so common that even the students in school are using it every day from out of cyber cafés and even their own personal PC’s at home.

PC video conferencing software is a browser-based video conferencing application that requires a simple installation via an Internet Explorer active-X plug-in or a FireFox extension. If you don't have the PC video conferencing software installed on your PC you can do so by going to the more popular sites such as Yahoo and Google or Skype and download their free versions of the PC video conferencing software. The downloading and installation is fully automated and you just have to sit back and watch the computer do it’s work. Once you have installed the software and are connected to the Internet you can take part in any PC video conferencing program on the Internet, of course you have to have access to the conference with a username or password.

Once launched the PC video conferencing software is very compact and simple to use. The few and simple controls PC video conferencing requires you to know are all easily accessible from the screen of the video window and they allow the user to freeze the video, mute the microphone or to access a simple menu containing access to the other key features of PC video conferencing.

Computer Memory

Computer Memory
From Wikipedia

A

computer's memory can be viewed as a list of cells into which numbers can be placed or read. Each cell has a numbered "address" and can store a single number. The computer can be instructed to "put the number 123 into the cell numbered 1357" or to "add the number that is in cell 1357 to the number that is in cell 2468 and put the answer into cell 1595". The information stored in memory may represent practically anything. Letters, numbers, even computer instructions can be placed into memory with equal ease. Since the CPU does not differentiate between different types of information, it is up to the software to give significance to what the memory sees as nothing but a series of numbers.

In almost all modern

computers, each memory cell is set up to store binary numbers in groups of eight bits (called a byte). Each byte is able to represent 256 different numbers; either from 0 to 255 or -128 to +127. To store larger numbers, several consecutive bytes may be used (typically, two, four or eight). When negative numbers are required, they are usually stored in two's complement notation. Other arrangements are possible, but are usually not seen outside of specialized applications or historical contexts. A computer can store any kind of information in memory as long as it can be somehow represented in numerical form. Modern computers have billions or even trillions of bytes of memory.

The CPU contains a special set of memory cells called registers that can be read and written to much more rapidly than the main memory area. There are typically between two and one hundred registers depending on the type of CPU. Registers are used for the most frequently needed data items to avoid having to access main memory every time data is needed. Since data is constantly being worked on, reducing the need to access main memory (which is often slow compared to the ALU and control units) greatly increases the computer's speed.

Computer main memory comes in two principal varieties: random access memory or RAM and read-only memory or ROM. RAM can be read and written to anytime the CPU commands it, but ROM is pre-loaded with data and software that never changes, so the CPU can only read from it. ROM is typically used to store the computer's initial start-up instructions. In general, the contents of RAM is erased when the power to the computer is turned off while ROM retains its data indefinitely. In a PC , the ROM contains a specialized program called the BIOS that orchestrates loading the computer's operating system from the hard disk drive into RAM whenever the computer is turned on or reset. In embedded computers, which frequently do not have disk drives, all of the software required to perform the task may be stored in ROM. Software that is stored in ROM is often called firmware because it is notionally more like hardware than software. Flash memory blurs the distinction between ROM and RAM by retaining data when turned off but being rewritable like RAM. However, flash memory is typically much slower than conventional ROM and RAM so its use is restricted to applications where high speeds are not required.In more sophisticated computers there may be one or more RAM cache memories which are slower than registers but faster than main memory. Generally computers with this sort of cache are designed to move frequently needed data into the cache automatically, often without the need for any intervention on the programmer's part.

Computer Program

Computer Program
From Wikipedia

In practical terms, a

computer program may run from just a few instructions to many millions of instructions, as in a program for a word processor or a web browser. A typical modern computer can execute billions of instructions per second (gigahertz or GHz) and rarely make a mistake over many years of operation. Large computer programs comprising several million instructions may take teams of programmers years to write, thus the probability of the entire program having been written without error is highly unlikely.

Errors in

computer programs are called "bugs". Bugs may be benign and not affect the usefulness of the program, or have only subtle effects. But in some cases they may cause the program to "hang" - become unresponsive to input such as mouse clicks or keystrokes, or to completely fail or "crash". Otherwise benign bugs may sometimes may be harnessed for malicious intent by an unscrupulous user writing an "exploit" - code designed to take advantage of a bug and disrupt a program's proper execution. Bugs are usually not the fault of the computer. Since computers merely execute the instructions they are given, bugs are nearly always the result of programmer error or an oversight made in the program's design.

In most computers, individual instructions are stored as machine code with each instruction being given a unique number (its operation code or opcode for short). The command to add two numbers together would have one opcode, the command to multiply them would have a different opcode and so on. The simplest computers are able to perform any of a handful of different instructions; the more complex computers have several hundred to choose from—each with a unique numerical code. Since the computer's memory is able to store numbers, it can also store the instruction codes. This leads to the important fact that entire programs (which are just lists of instructions) can be represented as lists of numbers and can themselves be manipulated inside the computer just as if they were numeric data. The fundamental concept of storing programs in the computer's memory alongside the data they operate on is the crux of the von Neumann, or stored program, architecture. In some cases, a computer might store some or all of its program in memory that is kept separate from the data it operates on. This is called the Harvard architecture after the Harvard Mark I computer. Modern von Neumann computers display some traits of the Harvard architecture in their designs, such as in CPU caches.

While it is possible to write

computer programs as long lists of numbers (machine language) and this technique was used with many early computers, it is extremely tedious to do so in practice, especially for complicated programs. Instead, each basic instruction can be given a short name that is indicative of its function and easy to remember—a mnemonic such as ADD, SUB, MULT or JUMP. These mnemonics are collectively known as a computer's assembly language. Converting programs written in assembly language into something the computer can actually understand (machine language) is usually done by a computer program called an assembler. Machine languages and the assembly languages that represent them (collectively termed low-level programming languages) tend to be unique to a particular type of computer. For instance, an ARM architecture computer (such as may be found in a PDA or a hand-held videogame) cannot understand the machine language of an Intel Pentium or the AMD Athlon 64 computer that might be in a PC.

Though considerably easier than in machine language, writing long programs in assembly language is often difficult and error prone. Therefore, most complicated programs are written in more abstract high-level programming languages that are able to express the needs of the computer programmer more conveniently (and thereby help reduce programmer error). High level languages are usually "compiled" into machine language (or sometimes into assembly language and then into machine language) using another computer program called a compiler. Since high level languages are more abstract than assembly language, it is possible to use different compilers to translate the same high level language program into the machine language of many different types of computer. This is part of the means by which software like video games may be made available for different computer architectures such as personal computers and various video game consoles.The task of developing large software systems is an immense intellectual effort.

Producing

software with an acceptably high reliability on a predictable schedule and budget has proved historically to be a great challenge; the academic and professional discipline of software engineering concentrates specifically on this problem.

CPU Designs

CPU Designs
From Wikipedia

The control unit (often called a control system or central controller) directs the various components of a computer. It reads and interprets (decodes) instructions in the program one by one. The control system decodes each instruction and turns it into a series of control signals that operate the other parts of the computer. Control systems in advanced computers may change the order of some instructions so as to improve performance.

A key component common to all CPUs is the program counter, a special memory cell (a register) that keeps track of which location in memory the next instruction is to be read from.
The control system's function is as follows—note that this is a simplified description, and some of these steps may be performed concurrently or in a different order depending on the type of CPU:
Read the code for the next instruction from the cell indicated by the program counter.
Decode the numerical code for the instruction into a set of commands or signals for each of the other systems.

Increment the program counter so it points to the next instruction.

Read whatever data the instruction requires from cells in memory (or perhaps from an input device). The location of this required data is typically stored within the instruction code.
Provide the necessary data to an ALU or register.

If the instruction requires an ALU or specialized hardware to complete, instruct the hardware to perform the requested operation.

Write the result from the ALU back to a memory location or to a register or perhaps an output device.

Jump back to step (1).

Since the program counter is (conceptually) just another set of memory cells, it can be changed by calculations done in the ALU. Adding 100 to the program counter would cause the next instruction to be read from a place 100 locations further down the program. Instructions that modify the program counter are often known as "jumps" and allow for loops (instructions that are repeated by the computer) and often conditional instruction execution (both examples of control flow).

It is noticeable that the sequence of operations that the control unit goes through to process an instruction is in itself like a short computer program—and indeed, in some more complex CPU designs, there is another yet smaller computer called a microsequencer that runs a microcode program that causes all of these events to happen.

Fix Computer History

Fix Computer History
From Wikipedia

It is difficult to identify any one device as the earliest fix computer, partly because the term "computer" has been subject to varying interpretations over time. Originally, the term "computer" referred to a person who performed numerical calculations (a human computer), often with the aid of a mechanical calculating device.

The history of the modern computer begins with two separate technologies—that of automated calculation and that of programmability.

The "castle clock", an astronomical clock invented by Al-Jazari in 1206, is considered to be the earliest programmable analog computer. It displayed the zodiac, the solar and lunar orbits, a crescent moon-shaped pointer travelling across a gateway causing automatic doors to open every hour, and five robotic musicians who play music when struck by levers operated by a camshaft attached to a water wheel. The length of day and night could be re-programmed every day in order to account for the changing lengths of day and night throughout the year.

The end of the Middle Ages saw a re-invigoration of European mathematics and engineering, and Wilhelm Schickard's 1623 device was the first of a number of mechanical calculators constructed by European engineers. However, none of those devices fit the modern definition of a computer because they could not be programmed.

In 1801, Joseph Marie Jacquard made an improvement to the textile loom that used a series of punched paper cards as a template to allow his loom to weave intricate patterns automatically.

It was the fusion of automatic calculation with programmability that produced the first recognizable computers. In 1837, Charles Babbage was the first to conceptualize and design a fully programmable mechanical computer that he called "The Analytical Engine". Due to limited finances, and an inability to resist tinkering with the design, Babbage never actually built his Analytical Engine.

Large-scale automated data processing of punched cards was performed for the U.S. Census in 1890 by tabulating machines designed by Herman Hollerith and manufactured by the Computing Tabulating Recording Corporation, which later became IBM.

During the first half of the 20th century, many scientific computing needs were met by increasingly sophisticated analog computers, which used a direct mechanical or electrical model of the problem as a basis for computation. However, these were not programmable and generally lacked the versatility and accuracy of modern digital computers.George Stibitz is internationally recognized as a father of the modern digital computer.Later models added greater sophistication including complex arithmetic and programmability.