A computer system is defined as combination of components designed to process data and store files.
Meaning of Input Process Output Storage Input is any data or instruction entered into the computer system for processing. The processing unit controls all activities within the system. Output is data that has been processed into a useful form, called information Storage is a location which data, instruction and information are saved for future use
Information Processing Cycle Process Output Input Storage Block diagram of Information Processing Cycle (CPU)
One byte represents one character such as A, 7, 9 and +.
Bit, Byte and Character Eight bits grouped together as a unit are called a byte . A byte represents a single character in the computer. bit byte character L.O :State the relationship of data representation: bit, byte and character.
ASCII pronounced as "ask-key" stands for the A merican S tandard C ode for I nformation I nterchange and was proposed by ASA (American Standard Association) in 963 and was finalised in 1968.ASCII is a standard of 7-bit code used to represent characters, which include letters, numbers and punctuation marks.
Step 2. An electronic signal for the capital letter T is sent to the system unit. Step 3. The signal for the capital letter T is converted to its ASCII binary code (01010100) and is stored in memory for processing. L.O :Explain the function of ASCII code. Step 1. The user presses the capital letter T (shift+T key) on the keyboard. Step 4. After processing, the binary code for the capital letter T is converted to an image, and displayed on the output device. T
This is how we get the calculation for 1024 bytes.
1 MB = 1 048 576 bytes or it can be said as:
1 MB = 2 20 bytes
1 GB = 1 073 741 824 bytes or it can be said as:
1 GB = 2 30 bytes
1 TB = 1 099 511 627 776 bytes or it can be said as:
1 TB = 2 40 bytes
Data Measurement L.O :State the units of data measurement Why is 1024 bytes = 1KB? 2 0 = 1 2 1 = 2 2 2 = 4 2 3 = 8 2 4 = 16 2 5 = 32 2 6 = 64 2 7 = 128 2 8 = 256 2 9 = 512 2 10 = 1024
Clock Speed Measurement L.O :State the units of clock speed measurement Every microprocessor contains a system clock. The system clock controls the speed of all the operations within a computer. The speed of the clock is measured by how many cycles per second the clock makes. The clock speed unit is measured in hertz . A hertz is one cycle per second. megahertz (MHz) equals to one million cycles of the system clock Gigahertz (GHz) equals to one billion cycles of the system clock
Which is faster ? Pentium 4 running at 2.4 GHz is approximately one-third faster than a Pentium 4 running at 1.8 GHz. One way of comparing the performance of personal computers is by comparing their microprocessor speeds . Microprocessor speeds are determined by their clock speed and are usually expressed in gigahertz (GHz), billion of machine cycles per second.
The more RAM a computer has, the faster it responds Also called main memory or primary storage Most RAM is volatile, it is lost when computer’s power is turned off Memory chips that can be read from and written to by processor
Memory chips that store permanent data and instructions Nonvolatile memory , it is not lost when computer’s power is turned off Three types: Firmware — Manufactured with permanently written data, instructions, or information EEPROM ( e lectrically e rasable p rogrammable r ead- o nly m emory)— Type of PROM containing microcode programmer can erase PROM ( p rogrammable r ead- o nly m emory)— Blank ROM chip onto which a programmer can write permanently