Types of Random access Memory (RAM)

SDRAM - another of those powerful acronym that describes a lot more than it sounds like it does. The letters stand for Synchronous Dynamic Random Access Memory, and it is a fast method of delivering computing capacity. SDRAM can run at 133 Mhz, which is much faster than earlier RAM technologies. Benefit of SDRAM is what is called pipelining. Because the SDRAM chips are so dense and complex, they can accept more than one write command at a time.

DDR RAM - Double-Data-Rate Synchronous Dynamic Random Access Memory, better known as DDR SDRAM or DDR RAM for short, is a type of very fast computer memory. DDR RAM is based on the same architecture as SDRAM, but utilizes the clock signal differently to transfer twice the data in the same amount of time. DDR is essentially twice as fast as SDRAM. Generally made for the processor 1GHz and faster.

Random DRAM - is Rambus Dynamic Random Access Memory a memory subsystem that promises to transfer up to 1.6 billion bytes per second. The subsystem consists of the random access memory, the RAM controller, and the bus (path) connecting RAM to the microprocessor and devices in the computer that use it. RDRAM is used mainly for video accelerator such as videocams using FireWire and the Accelerated Graphics Port (AGP).

EDO RAM -is stand for Extended Data Out RAM .A earlier dynamic RAM chip that improved the performance of fast page mode (FPM) memory in the mid-1990s. As a subset of fast page mode, it could be substituted for page mode chips. However, if the memory controller was not designed for the faster EDO chips, the performance remained the same as fast page mode.

SIMM - (Single in-line memory module) is a module containing one several access memory (RAM) chips on a small circuit board that connect to the computer motherboard. SIMMs typically come with a 32 data bit (36 bits counting parity bits) path to the computer that requires a 72-pin connector. SIMMs usually come in memory chip multiples of four megabytes.

Types of Application software...................

There is five types of application software. for example:-

1. Packaged software is Ready-made application software. In the early days of computing, any software that manufacturers didn't provide as part of the computer had to be custom-built to order.For example:-

• Microsoft Office - include many software programs that may be used in the office such as Microsoft Excel, Microsoft Word and Microsoft Access.
• Swift Install -allows the user to create a personalized installation program for his/her software, using an easy, graphical user interface. After the user has created the installation files, these files can be used by another person to install the software packaged in the installation files.
• Sound Sense -Sound Sense plays sounds that come packaged with it, and any new ones you import in. It also is an image viewer, where you can set an image to show when a certain sound plays.

2. Custom Software is a type of software that developed either for a specific organization or
function that differs from or is opposite of other already available software.It is generally
not target to the mass market, but usually created for companies, business entities, and
organization. For example:-

• Part Finder & Search tool - This software was designed for a business company. The software could allow sales staff to easily and quickly find parts based on specific specification.
  

3. Shareware is basically "try before you buy" software. Shareware distribution is letting
clients try the software before buying the full version, by downloading a trial version from
your website. Types of shareware programs:-

• The complete programs - the client can try and keep using it forever.However, the software author requires that the client registers the program and pays a fee, which is usually lower price.
• The trial period - the program has all its function, but it only last for a determine period of time, usually 30days. after that you have to pay for the software.

4. Freeware is software offered free of charge, downloadable off the internet. It is different from shareware in that the share requires a payment if the software is to be used past trial date. For example:-

• Mozilla Firefox
• Torrent
• QuickTime player
  

5. Public Domain Software refers to software that is no limited by having a copyright. It can thus be freely used, copied, or altered, because no one owns the right to restrict its use. For example - Linux operating systems.

Unicode VS ASCII code

Unicode

ASCII code

ACSII is stand for American Standard Code for Information Interchange. A coding standard for characters, numbers, and symbols that is same as the first 128 characters of ASCII character set but differ from remaining character.
The ASCII is divided into four group of 32 characters which is excluding the extended characters that define by IBM.

The first 32 characters is codes 0 through 1Fh, form a special set of characters. It is also called control characters.Control characters is capable to perform varios display control operation rather than displaying symbols.Unfortunately, different control characters perform different operation on different output devices.

The second group of 32 ASCII characters codes comprise varios punctuation symbols, special characters, and the numerics digits. The most common characters in this group include the:

• space characters (code 20h)
• numeric digits 0 -9 ( codes 30h - 39h)
  

The third group of 32 ASCII characters is use for alphabetic characters.The ASCII codes for the characters "A" through "Z" in the range 41h through 5Ah. Since there are only 26 different characters, the remaining six codes holds various special symbols.

The fourth, and the final group of 32 ASCII characters codes are used for the lower case alphabetic symbols, five additional special symbols. and anothercontrol character.

ASCII data is the standard for interchange across computer systems and programs. If you will program in the assembly language you will be dealing with ASCII characters.