Senin, 12 November 2012

Macam-macam virus pada komputer


Pengertian Virus adalah program yang dibuat oleh seorang programmer yang bersifat merusak.Virus menginpeksi file dengan eksetensi tertentu. Misalnya exe, txt, jpg dan lain sebagainya.Jenis – jenis virus bisa dibedakan menjadi beberapa bagian, yaitu :


a. Virus boot sector 
Merupakan virus umum, bersipat menggandakan diri dengan cara menindih bootsector asli pada sebuah disk, sehingga pada saat booting virus akan langsung dijalankan ke memori.


b. Virus file 
Menyerang file yang dijalankan oleh suatu system operasi. Biasanya menyerang com atau exe.


c. Virus direct action 
Virus ini akan masuk kememori untuk menjalankan file lainnya.lalu menajalankan program lain untuk menipu.


d. Multi partition virus 
Merupakan gabungan dari virus bootsector dan virus file.


e. Polymorphic virus 
Virus yang dirancang untuk mengelabui program AV. Yaitu mengubah struktur dirinya setelah menjalankan perintah.


f. Stealth virus 
Mengendalikan intruksi – intruksi level DOS dengan menguasai table interrupt.


g. Magro virus
  

h. Ditulis oleh bahasa pemrograman dari suatu aplikasi, sehingga bersipat flatform independent.



Sumber : http://phaul-heger.blogspot.com/2012/04/macam-macam-virus-komputer.html

Kamis, 01 November 2012

BUSINESS LETTER


1.   Definition of business letter

A business letter is a formal communication from an organization to its customers, the general public for their information, another Company or the Authorities.  It is often written in a standard format, and in formal language, compared to a private letter between two people who are well known to each other.  The business letter will show things like the address and best way to communicate with the business - by return letter , e-mail or telephone. In general, the letter will be directed to a specific person and be about one topic.  Sometimes, the business letter will be looking for a response, but might be to give important information about an up-coming change of address or telephone number.  The letter might give information about new developments - a new website; launch of a new product.  To allow the sender to handle any response more efficiently, the business letter might contain key information such as an internal reference from the sender or related to the product in question.

 2. Types of business letter
  • ·      Making An Inquiry
Make an inquiry when you are requesting more information about a product or service. This type of business letter tends to include specific information such as product type, as well as asking for further details in the form of brochures, catalogs, telephone contact, etc. Making inquiries can also help you keep up on your competition!
  • ·      Sales Letters
Sales Letters are used to introduce new products to new customers and past clients. It's important to outline an important problem that needs to be solved and provide the solution in sales letters. This example letter provides an outline, as well as important phrases to use when sending out a wide variety of sales letters.
  • ·      Replying to an Inquiry
Replying to inquiries are one of the most important business letters that you write. Customers who make inquiries are interested in specific information, and are excellent business prospects. Learn how to thank the customers, provide as much information as possible, as well as make a call to action for a positive outcome. 

3. Parts of business letter
 
·      Date - Date of writing. The month should be fully spelled out and the year written with all four digits October 12, 2005
(12 October 2005 - UK style). The date is aligned with the return address. The number of the date is pronounced as an ordinal figure, though the endings st, nd, rd, th, are often omitted in writing. The article before the number of the day is pronounced but not written. In the body of the letter, however, the article is written when the name of the month is not mentioned with the day.

·      The Inside Address - In a business or formal letter you should give the address of the recipient after your own address. Include the recipient's name, company, address and postal code. Add job title if appropriate. Separate the recipient's name and title with a comma. Double check that you have the correct spelling of the recipient 's name.

The Inside Address is always on the left margin. If an 8 1/2" x 11" paper is folded in thirds to fit in a standard 9" business envelope, the inside address can appear through the window in the envelope.

·      The Greeting - Also called the salutation. The type of salutation depends on your relationship with the recipient. It normally begins with the word "Dear" and always includes the person's last name. Use every resource possible to address your letter to an actual person. If you do not know the name or the sex of of your reciever address it to Dear Madam/Sir (or Dear Sales Manager or Dear Human Resources Director). As a general rule the greeting in a business letter ends in a colon (US style). It is also acceptable to use a comma (UK style).

44. Style Bussines Letter :

·      block style
·      semi-block style
·      fullblock style
·      indented style
·      simpliefied letter style