Monday, August 17, 2009

The Central Processing Unit (CPU)

Memory Buffer Register (MBR)
This register serves as an interface between the CPU and main memory. Anything needed by the CPU (instruction or data) is first placed here before it goes to its final destination (such as the accumulator, IR, PC or other registers). Also, anything in the CPU that is to be stored in main memory comes here first before being copied into the main memory at the location specified by the address contained in the MAR.

Memory Address Register (MAR)
When another instruction is needed in the IR, or a value is to be loaded into the accumulator, or an operand is needed to perform some arithmetic or logic instruction, this register contains the memory address where the desired information can be found. It also serves as a pointer to the location in memory where the contents of some CPU register is to be stored.

Instruction Register (IR)
A special register in the CPU that holds the bit pattern corresponding to the next instruction to be performed within the CPU. The Control Unit accesses this register to decide which circuits need to be activated.

Instruction Buffer Register (IBR)
It is a multipurpose register in a computer (or a microprocessor) system strictly dedicated to temporarily hold extra instructions and provide other functions within the processor.

Program Counter (PC)
This CPU register always contains the memory address where the next instruction to be performed by the CPU can be found. Its contents is copied into the MAR before an instruction is fetched from the main memory. While the instruction is being fetched, the Control Unit updates the contents of the PC so that it will again point to the next instruction to be performed.

Arithmetic Logic Unit (ALU)
The part of the CPU where arithmetic and logic operations are performed. Sometimes called the arithmetic unit.

In CPU, accumulator is a register in which intermediate arithmetic and logic results are stored. Without a register like an accumulator, it would be necessary to write the result of each calculation (addition, multiplication, shift, etc.) to main memory , perhaps only to be read right back again for use in the next operation. Access to main memory is slower than access to a register like the accumulator because the technology used for the large main memory is slower (but cheaper) than that used for a register.

Sunday, August 16, 2009

Organizational Architecture

Basically, computer organization is how operational attributes are linked togather and contribute to realize the architectural spesifications.

Computer architectural is more to the architectural attributes physical address, memory, CPU and how they should be made to coordinate with each others for future.

One important thing is, computer architecture comes before computer organization.

Characteristics of effective organizational design

<-> simplicity
<-> flexibility
<-> reliability
<-> acceptability

Wednesday, August 12, 2009


Unicode is a computing industry standard allowing computers to consistently represent and manipulate text expressed in most of the world's writing systems. Developed in tandem with the Universal Character Set standard and published in book form as The Unicode Standard, Unicode consists of a repertoire of more than 100,000 characters, a set of code charts for visual reference, an encoding methodology and set of standard character encodings, an enumeration of character properties such as upper and lower case, a set of reference data computer files, and a number of related items, such as character properties, rules for normalization, decomposition, collation, rendering and bidirectional display order (for the correct display of text containing both right-to-left scripts, such as Arabic or Hebrew, and left-to-right scripts)

As the conclusion...

Unicode provides a unique number for every character,
no matter what the platform,
no matter what the program,
no matter what the language.

Here is some example of unicode table...

Tuesday, August 4, 2009


ASCII stands for American Standard Code for Information Interchange. Computers can only understand numbers, so an ASCII code is the numerical representation of a character such as 'a' or '@' or an action of some sort. ASCII was developed a long time ago and now the non-printing characters are rarely used for their original purpose. Below is the ASCII character table and this includes descriptions of the first 32 non-printing characters. ASCII was actually designed for use with teletypes and so the descriptions are somewhat obscure. If someone says they want your CV however in ASCII format, all this means is they want 'plain' text with no formatting such as tabs, bold or underscoring - the raw format that any computer can understand. This is usually so they can easily import the file into their own applications without issues. Notepad.exe creates ASCII text, or in MS Word you can save a file as 'text only'

Extended ASCII Codes
As people gradually required computers to understand additional characters and non-printing characters the ASCII set became restrictive. As with most technology, it took a while to get a single standard for these extra characters and hence there are few varying 'extended' sets. The most popular is presented below.

Sunday, June 7, 2009


fuh.. penat! 5-6 Jun 2009, kazen aku kawin, kat Taiping... 5hb akad nikah, 6hb bersanding. Kenape penat? Disbbkan faktor penempatan yg terhad.. Lebih 5 keluarga (termasuk yg ada anak2 kecik) terpaksa berkongsi 1 rumah teres 2 bilik, dan 2 bilik air. Time management is very important! hahaha.. Btw, it's fun! bile lagi nak rase camnih!
Ade beberapa la gambar menarik... Let see...

normal mode

selepas adjust exposure compensation (baru ku tahu enset ku ade bende alah camtuh)

mak n abh aku + pengantin

sepupu sepapat kaum kerabat dan sebagainya...

with my kazen

with .... eerrrkkk... pengapit pihak perempuan kot.. ntah! ^^

Wednesday, June 3, 2009

B A K A R ! ! !

pukul 2.35 am

pukul 2.57 am

pukul 5.02 am

pukul 5.04 am (without proxy)

This is heaven!!! :)