Class blog starts

Day1
How computers work

Today we covered the basics of how computer works in aspects of user, application, OS and hardware. Acutally these four components are basics and all about what we need to operate computers.

First, users are obviously us. There are not much complexity on this phase; however, how we react to computers are the key factors for us. In the lecture, the professor gave us examples about a person who considers the computer as a monitor and does not care about the Box of PC itself. Like we see at this example, users are the main and the final operator of computers.

Second, we have covered hardwares. Hardwares are the physical machines that we have, so it can be a motherboard, a CPU, RAM memories etc. Even though we have a lot of components on computers, the core hardware to start discuss is the parts on the motherboard. Motherboard has Central Processing Unit(CPU) which mainly does the all procceing that a computer needs; so that, it is like a brain of a computer. What comes in the second to CPU is the memories. Memories are strongly related to CPU for processing; it is a place to put datas for processing temporary. Adding to the memores, the kind of memories we have on motherboards are Random Access Memory(RAM) which enables to read and write; on the other hand we have Read Only Memory(ROM) which cannot be rewritten, for example, CD-ROM. Acutally there is one more type of memory called Basic Input Output System(BIOS) which is the one contains the basic information for starting up a computer and this is installed on the motherboard from the first hand; and the basic being of BIOS is not replaceable; even though, it is still possible to make changes on some parts of detail of how you run the computer. These CPU and Memories are the core factors for the processing of a computer.

Now let's get into the relatively minor but still essential parts of computers. Hard Disc Drive(HDD) is the persistent storage which is in the opposite function compared to the RAM memories. it stores basically everything that need to be kept. The reason why it is called "hard" is that it has a real hard disc inside for storage. Comparative to that, we have Foppy Disc Drive (FDD) which uses a soft disc, but that is taken over by hard discs these days.

As other essential components of hardware, we have a graphic card, a network card and Human Interface Devises(HID). A graphic card generates the image that we see on a display. A network card is enables a computer to stay only to networks. HID are more likely to be physical devises which users get conections through, for example, a keyboard, a mouse, a monitor, a system of speakers etc.

That was the brief descriptives of the names in Hardwares; and now I would like to mention how they work in their processing. Currently, we have two major types of Hardwares which are 32 bits and 64bits. The difference we have here is that about how much RAM memories we can use. Proceeding to that what are bits? When usually CPU access to RAM memories to read and write, it uses the address of data which are presented as bits. Each bit is the representation of segregated particles inside of memores. So, if we have CPU with 32bits that means the CPU can use the memories up to 4GB because each bit contains the informtion represented by 0 and 1 signals; and having one bit address 32 times means 2*2*2*....... for 32times to provide conbinations which enable to address 4GB of information. In case of 64bits, it will be 2*2 for 64 times; thereby it will be 8GB of information to be used by that CPU. Adding to that the 64bit hardwares are so much faster than 32bit ones; however, on our daily basis, 64bit is simply overspec as a computer commodity. The professor gave us an example by methapers; 64bit is like a Lamborgini but do you need to drive to go school and back in the middle of city with so many traffic lights? It is still nice and fast but does it compensate for the cost to buy the supercar? Actually, Lamborgini will cost $240000 but we can have the enough satisfaction as tool with a nissan march or a toyota vitz which cost arround $10000.

Next, I would like to move on to the application sector. Application is the principle that the processing of a computer work; and its basis was created by Alan Turing who were a mathmatitian. He prepared the frame of the computer system with infinite long tape with divides into cells which are alike to bits on RAM memoreies, and finite simbols for locating them inside of each cells. These two infinite celled tape and finite symbols are used to make what we call "stateregister" process. This state register process goes along the states from 0 to 1, 1 to 2...... then, if state 0 is 1 as its simbol, we put one in there, and move on to state 2. The contiuous process of this is the state register process which is the fundemental principle for the applications.

Now, what do we have generally in applications in their overviews. There are basically three basic applications exist as languages according to levels of processing from a hardware to a user. The machine level language is simply called the machine language mainly used by CPU. It is purly consisted with 0 and 1 signals; and the sets of signals mean commands such as "add", "substuct" etc. For example, 0011 is a set of a cord meaning to add next two set of information. The next level of language is called the assembly language which is the one that assemble the results from machine language in CPU; and these machine language and assembly language are lower level languages.

After lower level language, I would like to move on higher level languages which human can understand as well. Actually higher level languages are the ones which complied from lower level language to observe something meaningful in human language; for example, the print "hello world" is complied from the processing from the machine language and the assemble language. The higher language which presents the compiled result in human language is called Abstruction language. Futhermore, we have interpreted language which presents more sophisticated presentations for human; for example, Peel, PHP, Ruby and Javascript. Adding to the compiling functions we have another type of compiler like langauge which is Bycodes, for example, Java and Python.

Those lower machine side language and higher human side language was about the factors consisting applications; so now, I would like to mention about the Operating System OS. Now, what is OS? It can be methaphered as installed inflastractures in your house. Your house is the hardware; and it has water lines, electricity lines, phone lines and internet lines. Then, thanks to those installation of inflastuctures inside your house you can use washing machines, TVs, telephones and internets. Thereby, if those washing machines and others are applications which satisfy our specific needs, the installed inflastuctures are the Operating System which enables those applications to run in your computer.

There are so many different types of OS in the world but major ones are windows, MacOSX, linix, unix and so on. Even though we have so many different OS, the basic functions are the same ;and the functioning components are also the same. As list of function components we have resource management which does coordinating and sharing. Application Programing Interface(API) and Graphic Utitlity Interface(GUI) are dealing with interfacing the applications and graphics more optimal to users. Program exercizes which deal with interapts from network cards and management of memories. Schedule and prioritize are about when and which process to undertake. Disk access will be accessing HDD in efficient use.


Now finally, I explained the four essencial factors for working computers which covered in class. The overveiw was a pretty good nuts shell. I appreciated.