Groups • Raghav and Ishita • Sanjoni and Saurabh • Garima and Ragini • Anmol, Janaki and Shauraya The British School, N.Delhi
Measuring Unit • BIT( Binary Digit) • Byte ( 1 Byte=8 bits) • 1 KB=1024 bytes • 1 MB=1024 KB • 1 GB = 1024 MB
RAM- Random Access Memory • Also known as Volatile Memory, Main Memory and Intermediate Access Storage. • Working memory. Switch off Welcome here.
ROM- Read Only Memory • Firmware – instructions that tells computer how to load Operating system • Types – PROM ( Programmable read only memory) • EPROM( Erasable Programmable read only Memory)
Secondary Storage Devices • Magnetic Storage Devices (Floppy Disk, Hard Disk, magnetic Tape) • Optical Storage Devices ( CD, DVD) • Removable Storage Device ( Pen Drive, Zip Drive, Jaz Drive)
Floppy Disk 1.44 MB of Storage Capacity
What happens when a disk is formatted? • All data is erased ( Quick Format) • Surfaces are checked for physical and magnetic defects and tracks and sectors are created again. ( Full Format)
Hard Disk Seek Time Rotational Time Access Time
Magnetic Tape- Structure R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 F1 F2 Inter Block Gap- IBG F3 F4 F5 F6 F7 F8 F10 Block
Magnetic Tape- IBG • An Interrecord gap is a break between data records on magnetic tape that serves as a safety margin for data overwrites.
Optical Storage Devices- CD • CD-R • CD – RW • Other backup Devices like USB Drive, Jaz Drive and Zip Drive.