Computer_memory

=COMPUTER BASICS - Memory= include component="page" page="menu-computers" editable="1" You can understand letters (a-z) and numbers (0-9) as well as sounds, sights and sensations. Computers must convert EVERYTHING they know into 0s and 1s - DIGITAL INFORMATION

A numbering system that has only two digits is a BINARY numbering system (You use a 10-digit numbering system called the DECIMAL system)

Information is stored as FILES on your computer system. Files require some quantity of "memory" - (ie. the Hard Drive, RAM, CD space) to hold them. This FILESIZE is typically measured in terms of BITS, BYTES, KILOBYTES, MEGABYTES, GIGABYTES and TERABYTES.


 * "1 BIT" is the SMALLEST unit of measurement we can use - it can store only one of two possible values (ie. 1 or 0; "true" or "false"; "on" or "off")
 * 1 BYTE = 8 bits clustered one after the other (ie. "10011010")
 * 1 KILOBYTE = 1024 bytes
 * 1 MEGABYTE = 1024 kilobytes (or 1024KB)
 * 1 GIGABYTE = 1024 megabytes (or 1024MB)
 * 1 TERABYTE = 1024 gigabytes (or 1024GB)
 * 1 TERABYTE = 1024 gigabytes (or 1024GB)


 * Your school server space allows 150MB of storage. Each student in the school has the same
 * We rarely express our file sizes in "bits" or even "bytes" these days - typical files are simply too large.

What are the storage capacities for each of the following devices:


 * 5.25" Floppy disc (600KB / 1.2 MB)
 * 3.5" Floppy disc (720KB / 1.44MB)
 * ZIP disc (100MB)
 * CDROM disc (700MB)
 * DVD+R (single layer) (4.71GB)
 * DVD (dual layer) (8.5 GB)
 * HD DVD (30GB / 51GB)
 * BluRay DVD (25GB / 50GB)

TEXT and FILESIZES
Find the PUPPY.JPG on our BTT Handouts server and use it for this exercise. In this course, it will become VERY important to know how big individual files are.

Determining Filesizes
You can see the size of any files on your disk by RIGHT-MOUSECLICKING the file, and opening up PROPERTIES...

In WIN98 and XP, there are THREE values shown for the filesize:

1. NEAREST UNITS (KB, MB or GB): 2. BYTES 3. STORAGE BYTES USED

Examine the properties of the CYBERDOG.BMP file, and you'll see it listed in Megabytes (MB), but if it were much smaller, it might be expressed in Kilobytes (KB), or Gigabytes (GB) if it were much larger
 * 1. NEAREST UNITS:**

This is the same value as shown above, but is expressed in terms of BYTES. There are actually 1024 bytes in a Kilobyte, and 1024 Kilobytes in a Megabyte. This is why the number is not just an easy multiple of the “Nearest Units” number.
 * 2. BYTES:**

This is the amount of DISK SPACE required to hold the file. Hard Disks often “waste” disk space when storing small files, much like you “waste” a space on a full sheet of paper when you write a single phone number.
 * 3. STORAGE BYTES USED:**

Filesize Exercise:
Examine the properties of files you have on your H: drive; you MAY see them listed in Megabytes (MB), OR Kilobytes (KB), or maybe even BYTES. What is the LARGEST file you have on your server so far? What is the LARGEST file in the MAY HANDOUTS server (not just the ones in BTT)? Record your results in the "Filesizes" Doc.