Unit C-Hardware & Software1 GNVQ Foundation Unit C Bits & Bytes

What you Need to Learn: What a bit is What a byte is Range of RAM capacity Floppy disk capacity Range of hard disk capacity Common CPU makes Typical CPU speeds About This Lecture: 1.You will learn about bits & bytes 2.You will learn about typical storage capacities of storage devices such as floppy disks and hard drives 3.You need to understand what RAM capacity is measured in 4.You need to know about CPU makes and how we measure CPU speed.

Binary Digits - Bits What does the following mean Computers store Digital Data –Example –(the letter A would be stored as ) –(the letter B would be stored as )

Binary Digits - Bits BinaryCHR A B C D E F G H I J K BinaryCHR L M N O P Q R S T U V BinaryCHR W X Y Z We can work out the meaning of… from the table

BinaryCHR A B C D E F G H I J K BinaryCHR L M N O P Q R S T U V BinaryCHR W X Y Z Binary Digits - Bits What is the meaning of…

Binary Digits - Bits Imagine RAM memory cells –Each cell has 8 capacitors that can be –charged (1) –Not charged (0) so starting from the top memory cell and reading down. This set of memory cells says….?

Bytes 8 bits equals 1 byte How many bytes are shown in the diagram?

Data Size Terms used to describe the size of data or storage capacity –Bit (binary digit-smallest data item) –Byte (8 bits) –Kilobyte (1024 bytes or 2 10 ) –Megabyte (1,048,576 bytes or 1024 kilobytes or 2 20 ) –Gigabyte (1,073,741,824 bytes or 1024 megabytes or 2 30 ) –Terabyte (~1,099,000,000,000 or 1024 gigabytes or 2 40 )

Floppy disks store data on magnetically on a circular magnetic disk Floppy Disk Capacity 1.44MB storage capacity That’s 1.44 million bytes. Imagine 1.44 million letter A’s

Hard Disk Capacity 512MB storage capacity Hard disk capacity varies Disk capacity for an old 486 computer 8GB storage capacity Typical disk capacity for a newer Pentium II 80GB storage capacity Typical disk capacity for a new Pentium 4 About 350 floppies About 5700 floppies About 57,000 floppies

RAM Capacity RAM capacity varies 32MB RAM In an old 486 computer 128 MB RAM In a newer Pentium II 512MB to 1.5GB RAM In a new Pentium 4

CPU Makes Manufacturer: Most popular CPUs for Personal Computers (PC) are made by Intel. Other CPU manufacturer’s are AMD and Cyrix. Generation: Each generation of CPUs is more powerful than the last. Newer CPUs can process more instructions at a time. Generations include 286, 386, 486, Pentiums, Pentium MMX, Pentium II, Pentium III and currently Pentium 4.

CPU Speeds Speed: Each CPU generation is available in different speeds. The CPU speed is a major factor in determining how fast a computer operates. Generally, t he faster the speed, the faster the computer operates. The speed of a CPU is measured in megahertz (MHz or GHz).

CPU speeds vary 50MHZ In an old 486 computer 500MHZ In a newer Pentium II 2200MHZ or 2.2GHZ In a new Pentium 4 CPU Speeds Hertz means cycles per second So, 50MHz means 50 million cycles per second

The End