Computer Systems I’m ONLY a machine! Ashkarali P Asst. Professor GCM Wayanad Ashkarali, GCM

Hardware Hardware refers to all the parts of the Computer System that we can touch. An item of hardware is called a device. Microprocessor Main memory Input / Output Backing Storage Ashkarali, GCM

Central Processing Unit CPU RAM Backing Storage Input Output ROM Ashkarali, GCM

The Processor Carries out the actual process Follows a set of instructions called a program Ashkarali, GCM

Representing Graphics & Text Bit-Mapped Graphics –Dots called pixels –Each pixels is either On (1 – black) or Off (0 – white) Text – ASCII standard file format – = MUJTABA BE QUIET Ashkarali, GCM

Units of Storage Binary UnitValue Bit1 or 0 Byte8 bits Kilobyte (KB)1024 bytes Megabyte (MB)1024 Kilobytes Gigabyte (GB)1024 Megabytes Terabyte (TB)1024 Gigabytes Ashkarali, GCM

Main Memory CPU RAM Backing Storage Input Output ROM Ashkarali, GCM

Main Memory Where the computer stores programs & data Types: –RAM Random Access Memory –ROM Read Only Memory Ashkarali, GCM

Main Memory RAM Chip –Temporary storage –Data is lost when computer switched off –Data can be written to RAM –Upgrading is easy with RAM Chips ROM Chip –Permanent storage –Data is safe when computer is switched off –Data can not be added to ROM –Some OS are stored on ROM Chips Ashkarali, GCM

Input CPU RAM Backing Storage Input Output ROM Ashkarali, GCM

Input Devices (Navigational) Mouse Trackball Track pad Touch Screen Joystick SmartBoard Ashkarali, GCM

Input Devices (Data Input) Keyboard Graphics Tablet Scanner Digital Still camera Digital Video Camera Webcam Microphone Ashkarali, GCM

Backing Storage CPU RAM Backing Storage Input Output ROM Ashkarali, GCM

Backing Storage Method used to physically store data. Constantly increasing in capacity to meet demands. Magnetic Storage –Floppy disc, Hard Disc, Magnetic Tape Optical Storage –CD, DVD Solid State –USB Flash Drive Ashkarali, GCM

Drive or Media DriveMedia Ashkarali, GCM

Magnetic Storage Hard Disk Drive –Usually main type of backing store –Non-removable media Floppy Disk –Plastic disk with rectangular cover –Removable media Magnetic Tape –Sequential Access –Think VHS tape –Removable media Ashkarali, GCM

Optical Storage Ashkarali, GCM

Optical Storage CD-ROM –Read by a laser beam that reflects of surface “pits” and “lands” DVD-ROM –Similar to CD but with larger capacity because of multiple layers CD-Recordable (CD-R) / DVD-R –Write Once, Read Many CD-Rewritable (CD-RW) / DVD-RW –Still uses a laser but contents can be changed Ashkarali, GCM

USB Flash Drive Universal Serial Bus: –Computer interface used by different devices. Solid State Memory –No moving parts Advantages –Portable –Can have large memory (currently 8GB) Ashkarali, GCM

Flash Memory Cards Solid State Memory –No moving parts –Used in cameras and mobile phones Advantages –Portable –Can have large memory (currently 8GB) –Can be read by a card reader Ashkarali, GCM

Output CPU RAM Backing Storage Input Output ROM Ashkarali, GCM

Output Devices Printer –Laser –Inkjet Comparison of Printers Resolution –Dots Per Inch (DPI) Speed –Pages Per Minute (PPM) Cost –Capital Cost –Running Costs Ashkarali, GCM

Output Devices Plotter Monitor (VDU) LCD –Liquid Crystal Display TFT –Thin Film Transistor Multimedia Projector Speakers Ashkarali, GCM

Types of Computer Desktop Laptop/Notebook Palmtop Ashkarali, GCM

Types of Computer Mainframe Ashkarali, GCM