Computer Systems Flashcards
(55 cards)
overflow
the calculation goes over the amount of bits the computer can deal with
Binary
A way of representing information using only two options.
Hexademical
easier to read as a human
ASCII
American Standard Code for Information Interchange
extended ASCII
8 bit which can code for all foreign characters
Unicode
can fit all language characters and more
colour depth
the number of available colours is 2^(n)
Image file size (bits)
Image size (area) x colour depth
Sampling
converting analog sound to digital sound
Sample rate
the number of samples taken per second
Bit depth (sound)
how many bits is used
Sound file size (in bits)
Sample rate x Bit depth x Time running (seconds)
compression
reducing file size
Lossy compression
Losses bits of data by using abstraction and then filling in with what it predicts
Lossless compression
No data is lost. Repeats recurring information
Huffman tree
A tree having the nodes representing symbols as the leaves, with more frequent symbols having nodes progressively closer to the root. The most frequent symbols are the closest to the root node. Note that internal nodes cannot represent symbols.
The edges connecting children to parents are either 0 or 1. Convention must be established (e.g., left children have 0s, right children have 1s).
The code for a symbol is built from 0s and 1s along the path from the root down to the desired symbol.
Codes must be prefix free.
abc:7
/ \
ab:3 c:4
/ \
a:1 b:2
Run Length Encoding (RLE)
wbbw becomes 1w2b1w
System Software
System that manages the operation of the computer (controls hardware)
Embedded system
Coded for 1 purpose (washing machine)
CPU (Central Processing Unit)
Where data processing takes place
FDE (Fetch Decode Execute) cycle
Data fetches information, decodes it and then executes task
Control Unit (CU)
controls operations of the CPU’s internal components
Address bus
These transfers data to and from the CPU
Control bus
Controls whether the busses are occupied
