Data Storage Flashcards
What is a gate?
A device that computes a Boolean operation
Flip-Flop
A circuit built from gates that can store one bit.
Most and Least significant bit
Most—>Left
Least—>Right
Main Memory Addresses
-Addres :
A “name” that uniquely identifies one cell in the computer’s main memory
RAM
Random Access Memory
-Memory in which individual cells can be easily accesed in any order
DRAM
Dynamic Memory
-RAM composed of volatile memory
KB
MB
GB
2^10 bytes
2^20 bytes
2^30 bytes
Mass Storage
+Additional Devices
-Magnetic Disks
-Magnetic Tape
-CDs
-DVDs
-Solid-state Disks
-Flash Drives
Mass Storage
+Advantages over main memory
-Less volaitility
-Larger storage capacities
-Low cost
-On many case can be removed
+Additional Devices
-Flash Drives
> Flash Memory : Circuits that traos electrons in tiny cilicon dioxide chambers
Repeated erasing slowly damages the media
Mass storage of choice for : Digital cameras and -Smartphones
SD Cards : provide GBs of storage
Representing Text
ASCII : Uses patterns of 7-bits to represent most symbols used in written English text
ISO : Developed a number of 8-bit extensions to ASCII, each designed to accomodate a major language group
Unicode : Uses patterns up to 21-bits to represent the symbols used in languages world wide, 16-bits for world’s commonly used languages
Limitations of computer representations of numberic values
Overflow : When a valıe is too big to be represented
Truncation : When a value cannot be represented accurately
Storing Integers
Two’s complement notation : the most popular means of representing integer values
Excess notation : Another means of representing integers
**Both can suffer from overflow errors
Storing Fractions
Floating-point Notation :
Sign bit Exponent Mantissa
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What is a programming language?
Is a computer system created to allow humans to precisely express algorithms using higher level of abstraction
