How Computers Count

How Computers CountThe world around us has many aspects which work in the same way as a computer. There are many examples of opposites, for instance Up and Down, Left and Right, Forwards and Backwards. A light may be On or Off, maybe it’s Night or Day. Yes or No? You can think of many others.

This system of two possible states is called a Binary System. If it’s not one, it must be the other.

A computer uses the Binary System to perform all its functions. The basic unit, originally made from a vacuum tube, then a transistor, then a chip, is used thousands of times over to make the total unit. The light being On or Off which we mentioned above is controlled by a switch. In the computer this switch is a transistor, which is either On or Off.

The Binary system is a Number System. You are familiar with the Decimal system which has 10 numerals 0 to 9 (think like a computer 0 comes first). You can make up all sorts of number systems for whatever purpose you want. You probably know about a dozen (12) and have also heard of a half dozen.

If you’ve used your computer much you may have come across the Hexadecimal system. This one has 16 ‘numerals’ 0-9and A-F. Another number system used by computer people is the Octal system which has 8 numerals, 0-7.

So, how do we count with only 0 and 1. Simple, in exactly the same way you count in decimal. The first ten numbers are OK, 0-9, but what next? We start again but add in a 1 making 10 or “one, zero”. This gets us to “one, nine” and we go to “two, zero”, and so on up to “nine, nine” then we again add a 1 to make 100 – “one, zero, zero.”

DECIMAL 0-9, 10-19, 20-…..-99, 100.

In the Binary sequence, it’s much simpler. Starting off at zero we have 0,1 – and that’s it. We follow the same rule and add in a 1, making “one,zero”. Next come “one, one”; then “one, zero, zero”; -“one, zero, one”; etc. These are equivalent to Decimal 0,1,2,3,4,5. How does this relate to computers? That’s next.

BINARY – 0 1 10 11 100 101

DECIMAL- 0, 1, 2, 3, 4, 5

In our computer we have transistor switches, as described above. For the math example we just looked at, we need 3 switches. These each represent a Binary Digit, or Bit. To represent a Decimal 1, these switches would be OFF,OFF,ON or 001. For a Decimal 5 we would have ON,OFF,ON, or 101. By extension you can see that with 4 switches we could go to 1111 or 15 Decimal.

TRANSISTORS [OFF OFF ON] [ON OFF ON] [ON ON ON ON]

BINARY…… 001 101 1111

DECIMAL….. 1, 5, 15

Another point to note is that each binary digit, or bit, has a value. Just as in Decimal we have units, tens, hundreds, etc. in Binary the values are 1,2,4,8,16,32,64,128 etc. etc. The binary code 1111 mentioned above is thus 1+2+4+8=15. what would BINARY 1010 be in decimal?

BIT VALUE 8 4 2 1

BINARY…. 1 0 1 0

DECIMAL… 8+2=10

If you wanted to work out what binary 100101100 was in decimal, you could add up the individual values. In fact people who work on the basic machines need to know “machine code”! To them 1010 would be A in Hexadecimal or 12 in octal.

One of the reasons for using the octal or hexadecimal code is to enable humans to interpret machine codes. Some mainframe computers use ‘words’ composed of 24, 32, 36 or 72 bits. These are displayed or printed in groups of three for octal, or four for hexadecimal. For example the 24 bit binary word in a computer may be interpreted as shown here.

BINARY 100 111 000 011 010 000 011 100

OCTAL.. 4 7 0 3 2 0 3 4

BINARY 1001 1100 0011 0100 0001 1100

HEX…. 9 D 3 4 1 D

This probably seems a very long-winded way to work out numbers, until you remember that these ‘switches’ can operate at nanosecond speed, in the order of 1,000,000,000 times per second, large calculations become possible.

Cleaning the Clogged Printhead

Cleaning the Clogged PrintheadIf your inkjet or bubblejet printer has clogged printheads there are 2 possible reasons:

Ink has dried in the nozzles

It is important to note that although genuine inks have anti-clogging agents in their formulation, if you have not used your printer in a long time the ink will dry up in the printhead. With genuine inks a couple of head cleans will usually get the ink flowing again.

If you are using refill or compatible cartridges more aggressive head cleans may be necessary. You may need printhead cleaning solution. The best way to stop ink drying in the printhead is to use your printer every week. Just print out a test page which will use black and colour.

Foreign matter has blocked the holes in the nozzles.

This is caused by foreign matter in the ink – always from small unfiltered particles from refill ink or lower quality compatible cartridges manufactured in a dusty environment – or the printhead collecting paper dust from poor quality paper, or the printhead picking up muck in an overfull parking station.

What is a parking station? This is where the printhead sits when the printer is not printing, usually on the right hand side inside the printer. There is a small rubber cap here which sits under the printhead to protect and prevent it drying out. On most printers it also provides a cleaning function and there is a lot of waste ink in this area- so it is the perfect place to collect dust and muck.

You can get a cotton bud in there and clean it by switching the printer off then on, and then when the printhead moves away from the parking station switch the printer off at the wall. You will then be able to access this area for cleaning.

If foreign matter in the ink has blocked the printheads and your printhead is fixed into the machine, put new original cartridges in your machine as this will usually dissolve any particles in the printhead. If your printhead is removable, take it out of the machine and sit it in about 5ml of very hot (not boiling!) water for a few minutes.

Dry thoroughly and re-insert into the machine and do a couple of printer head cleans. Repeat until the nozzles are unblocked. Always use good quality inks or compatibles in your printer – original inks are always best.

If you open your printer and you can see a fine white powder inside the machine, this is paper dust. This is getting into the print nozzles!

Always use good quality paper and once in a while use compressed air to clean out the inside of your printer (use a can of compressed air, not compressed air from a compressor – or you’ll blow away the electronics in your printer!).

Basic Equipment for Computer Network

Computer NetworkA computer network is a connection between two or more computers that is connected with cable or wireless device. Other peripheral devices that can be connected with computer can also be included in this network such as wireless receivers, printers, scanner, camera, etc.

This connection will make the information or data sharing between each computer and terminal become easier and less time consuming. Every computer and other devices inside a network are called a node.

There are no limits how much nodes that can be connected to a single network. Many big organizations could have millions of nodes in their network.

To make a network connection between nodes, it will require several tools or equipment. Here are some of the most important tools to make a network.

Network cabling

Cabling is use to connect a node to the central hub. These days many organizations are using fiber optic cable that have better ability in sending the data for their network cabling.

Network Adapter

This interface device can be found inside the computer and wireless receiver or router. This device will transfer and receive the data or information to and from the central or hubs. The adapter will influence the speed of data transfer in the network.

Hubs

This is the main device that gathers and connects all the nodes to become a network. The size of hubs depends on how many nodes that is in the network. For large network, it will require many hubs to be able to support many nodes.

Switches

Switches act as a terminal to control the data traffic between nodes and also hubs. It will connect a data from a node to its destination node correctly, more effectively and efficient. Therefore the data transfer will not crash to other data from different nodes that will make the connection halted or crash. A switch is also use to connect nodes that has different speeds to other nodes, so the connection speed will improve.

Should I Buy A Laptop Or A Desktop PC?

Laptop Or Desktop PC?You may find yourself asking that question many times while shopping for a computer. This guide offers you the pros and cons of owning a laptop versus a desktop PC.

Processing speed

Comparing processing speeds, laptops usually lag behind their desktop counterparts. With the rapid advance in microchip technology, the gap between them will become smaller.

Wireless

Most laptops come with wireless capability out of the box. This means you can get online from any location at home easily without ugly wires if you have a wireless network setup at home. Desktop PC do not typically provide this capability out of the box.

Memory

Memory chip tends to be more expensive in Laptop than desktop PC. If you buy a laptop then be prepare to pay more for memory upgrades than you have to with a desktop PC.

Graphics Display

Because of the size of a laptop, most business or entry level laptop use integrated graphics with limited ram. This means most laptops even some expensive ones cannot run graphics intensive applications or 3d games as well as a desktop pc. With a desktop pc, you can buy a dedicated graphics card just to serve a graphics intensive application.

Portability

Portability is why everyone wants a laptop these days. Because of their size and weight, it is easier to carry a laptop around as opposed to a desktop PC.

Screen Display

Everyone buy laptop for their portability so laptops usually do not come with screens as big as their desktop counterparts. The screen technology used is usually not as good as those used by desktop pc. Furthermore with a desktop pc, you can always upgrade to a bigger and better screen whereas for laptop you are stuck with the same screen display for the whole lifespan of the laptop.

Upgradeability

Laptops do not offer many upgrade options. You can only upgrade memory and hard disk. With a desktop you can upgrade almost anything and only limited by the motherboard. This means a cheap desktop pc offers a longer lifespan than a laptop.

So whether you should buy a cheap laptop or a cheap desktop, ask yourself what are your needs? If you want to be able to use a computer wherever you go, then you are looking at a laptop to fulfill your needs. However if you do not require the portability of a laptop, play a lot of 3D games, graphic intensive applications, if you care about upgradeability to prolong the lifespan of your investment, then desktop PC is a smarter choice for you.