HOW IT WORKS …
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WHAT IS A COMPUTER?
• A COMPUTER IS AN ELECTRONIC DEVICE FOR RETRIEVING, STORING AND PROCESSING DATA ACCORDING TO A VARIABLE PROGRAM
• COMPUTERS ARE NOT AS SMART AS WE MAKE THEM TO BE, THEY CANNOT FUNCTION OUTSIDE OF WHAT WE TELL THEM TO DO
WHAT’S INSIDE?• MOTHERBOARD: A CIRCUIT BOARD WHICH
CONTAINS THE PRINCIPAL COMPONENTS OF A COMPUTER AND PORTS FOR OTHER CIRCUIT BOARDS TO BE CONNECTED/SLOTTED
• A MOTHERBOARD WILL FUNCTION VERY SIMILARLY TO A LEGO BOARD
CPU
• CENTRAL PROCESSING UNIT
• BASICALLY FUNCTIONS AS THE “BRAIN” OF THE COMPUTER
• EVERYTHING GOES THROUGH THE PROCESSOR
• FUNCTIONS:
1) INPUT/FETCHES DATA
2) PROCESSES/DECODES DATA
3) OUTPUTS/EXECUTES DATA
4) STORES DATA
CPU (THINGS TO KNOW)
• PROCESSING SPEEDS, READS BITS OF INFORMATION AT A TIME
• HERTZ – PIECES OF INFORMATION PER SECOND
• EX: 2.2 GHZ (2.2 BILLION “PIECES” PER SECOND)
• MULTI-CORE PROCESSORS
CPU (WHAT’S INSIDE OF IT?)
• TRANSISTORS: BASICALLY SWITCHES THAT RUN AND ARE PROGRAMMED ACCORDING TO AN ELECTRIC CURRENT
• CIRCUITED IN A WAY THAT REPRESENTS A DECISION TREE
• ENIAC (1945)
• MOORE’S LAW: THE NUMBER OF TRANSISTORS IN A SPACE WILL DOUBLE EVERY TWO YEARS
MEMORY (RAM)
• THERE ARE TWO TYPES OF MEMORY: RAM VS. STORAGE
• RAM (RANDOM ACCESS MEMORY)
• COMPARATIVE TO “WITHIN ARM’S REACH” MEMORY STORAGE
• “RANDOM” BECAUSE COMPUTER CAN ACCESS ANYTHING ON RAM QUICKLY, AS OPPOSED TO FINDING IT’S PLACE LIKE ON A CASSETTE PLAYER
• MEMORY IS LOST WHEN COMPUTER IS SHUT DOWN, DEPENDENT ON ELECTRICITY, CONSTANT CURRENT
• MORE RAM, GENERALLY MEANS FASTER COMPUTER (512 MB, 4 GB)
MEMORY (HARD DRIVES)
• STORAGE MEMORY: LONG-TERM DATA STORAGE, COMPARATIVE TO BOOKSHELVES, CLOSETS
• RUNS ON ELECTRICITY BUT DATA IS NOT ERASED WHEN IT IS POWERED OFF, “PERMANENTLY WRITTEN”
• MUCH BIGGER CAPACITY, BUT MUCH SLOWER SPEEDS
• GENERALLY MORE THAN 256 GBS, 500 GBS, 1 TB
MEMORY (HARD DRIVES)
• SATA (MECHANICAL) VS SSD (NO MOVING PARTS – RANDOM ACCESS)
*SSD STORES DATA IN TRANSISTORS CALLED FGMOSFET (FLOATING GATE METAL OXIDE SURFACE FIELD EFFECT TRANSISTOR)
INPUT DEVICES
• INPUT DEVICES ALLOW US TO COMMUNICATE WITH OUR COMPUTERS BY CONVERTING INFORMATION INTO A FORMAT THAT THE COMPUTER CAN UNDERSTAND (1’S AND 0’S)
• KEYBOARD, MOUSE, MICROPHONE, TOUCH SCREEN, WEBCAMS, ETC.
OUTPUT DEVICES
• OUTPUT DEVICES ALLOW COMPUTERS TO COMMUNICATE WITH US IN A WAY THAT WE WOULD UNDERSTAND
• MONITORS, SPEAKERS, PRINTERS, ETC.
HARDWARE VS. SOFTWARE
• HARDWARE IS RIGID, AND CANNOT PERFORM TASKS THAT WERE NOT ORIGINALLY DESIGNED FOR THE DEVICE
• SOFTWARE IS FLUID AND CAN BE EASILY CHANGE
• SOFTWARE IS A SET OF INSTRUCTIONS THAT TELL THE HARDWARE OF THE COMPUTER HOW TO BEHAVE