This week was all about the ways data can be represented.  Exciting as always, for once this actually made sense and was interesting as we looked at how images are stored and represented so there was a link with the rest of the course.

Alphanumeric data:

This covers the keyboard mainly and how every key on the keyboard has its own unique code. There are three main ways to code this type of data:

• ASCII – which is a 7 bit code so this will represent 128 character. This isn’t a lot of characters really.
• ABCDIC – this is  more efficient than the ASCII system as it is an 8 bit code and can represent 256 characters, now including many more of the symbols.
• UNICODE – the best code there is for alphanumeric data. It is a 16 bit code so there are a possible to represent 65536 characters. So there are now sufficient codes for all the different symbols used in almost all languages and special characters like umlaut etc . OUt of the total number of codes 40,000 have already been defined leaving the rest either reserved for private use or for future expansion of programs.

Images:

• Bitmaps
• JPEG
• GIFF

These aren’t so easy to write about but for me were more interesting as now i can apply this to photoshop etc.