It is a transistor, the transistor is information itself. The transistor is so simple but it is the foundation of all our modern computers. To understand its impact we need to understand the history and science behind this.
History Of TransistorBefore the transistor existed we used vacuum tubes which are bulky evacuated glass bulbs. The triode vacuum tube consisted of three parts: the cathode, grid and anode.
The current is passed through the cathode and it begins to heat up causing it to release electrons. As gases have been removed from the tube the electrons have very little resistance to their movement and they are attracted to the positively charged anode. This completes the circuit and current flows. But we can manipulate this flow of electrons in many useful ways with the grid
The world's first general-purpose electronic computer the ENIAC used 18,000 vacuum tubes to perform calculations designed by John Mauchly and J. Presper Eckert. It was completed in 1945, it was purpose-built to calculate trajectories for artillery during World War II. A calculation that would take a human a day to calculate took ENIAC, 30 minutes but this thing weighed 30 tons and took up an entire room.
How Transistor Work?The transistor is in your CPU or microscopic and is manufactured with incredible precision with machines on thin wafers of silicon crystals that are sliced off silicon ingots. So what makes silicon so special that an entire section of the San Francisco Bay Area has been nicknamed after the material?
Now if we introduce those impurities to this pure silicon crystal we can change how it conducts the current. If we add phosphorus which has five electrons in its valence shell the extra electron is left free to roam the crystal structure. This extra electron makes the N-type negatively charged which is where the name comes. From the P-type is positively charged because it is doped with Boron which has three electrons in its valence shell. This structure wants to gain its final electron and will steal electrons from its neighboring atoms. This creates a mobile positive charge called a hole.
Free electrons in the N-type were migrated over to fill those holes in the P-type. This creates a boundary layer called the depletion layer which prevents more electrons passing through due to the negative charges repelling each other but when a positive voltage is applied to the base it negates the depletion layer and allows current to flow through completing the circuit. As you can see this is very similar to the function of the vacuum tube so how exactly does this allow computers to perform all these complex functions.
The first bit represents 1 the next 2 then 4 and finally 8 added up that equals 15. This pattern continues with each successive bit representing double the previous so we can add an additional bit if we want to count up to 31
Let's add 5 and 6 together to do this we want the circuit that will hold a 1 in the position as shown in the image. When either 1 and carry the 1 forward when both are 1. As you can see this will give us the number 11. The simplest circuit that can do this is a half adder which contains two types of logic gates. These are devices that can modify the binary code they are built using transistors.
The first is the XOR logic gate which gives a 1 only when one of the inputs is 1 if both are 0 or 1 it gives a 0.
The second logic gate is an AND gate which gives a 0 for everything except when both inputs are 1.
The co-founder of Intel, Gordon E. Moore noticed a trend in 1965 that the density of transistors on integrated circuits doubles every two years that trend has held until very recently but it is starting to slow down. One of the reasons for this is the less well-known of Moore's predictions. Moore second law or rocks law which states that the cost of manufacturing these devices will double every four years.
Intel made an announcement last year that the rate of advancement was slowing for these reasons. It's getting more and more difficult for chip manufacturers to shrink their product while maintaining profit.
Some want to harness quantum mechanics to perform calculations faster than any transistor ever could. Others want to decentralize computing power and create the so-called Internet of Things. Intel has said themselves that they plan to shift their focus from increases in speed to decrease in power consumption. One thing is for sure the computer industry will have to redefine itself in the near future.