Computer Abstractions and Technology

What three different classes/applications are computers used in?

Personal Computers (PC), servers, and embedded computers

Personal Computer (PC)

The best known form of computing

Servers

designed for large workloads

Embedded computers

the largest class of computers with the widest range of applications and performance

What timeperiods a primary constraint on performance was the size of the memory?

1960s-1970s

Algorithm affects performance how?

Determins both the number of source-level statements and the number of I/O operations executed

Programming language/ complier/ and architecture affect performance?

determines number of computer instructions for each source-level statement

Processor and memory system affect performance how?

Determines how fast instructions can be executed

I/O system (hardware and operating system) affect performance how?

determines how fast I/O operations may be executed

What are the 7 great ideas in computer architecture?

-Abstraction

-common case fast

-Parallelism

-Pipelining

-prediction

-Hierarchy of memories

-dependability via redundancy

Abstraction to simplify Design

lower level details are hidden to offer a simpler model at higher levels

make the common case

easier to make a fast sports car than fast minivan

performance via prediction

in some cases it can be faster on average to guess and start working rather than wait and know for sure

dependability via redundancy

make systems dependable by including redundant components that take over when failure occurs and helps detect them

What typical application may consist of millions of lines of code?

word processor

What executes low-level instructions?

hardware

What is needed to interpret or translate high-level operations into simple computer instructions

layers of software

What are the two types of system software that are central to every computer system today?

operating system and complier

What handles basic I/O operations, allocate storage and memory, and provides protected sharing of computer among applications?

OS (operating system)

What translate programs written in high-level language into instructions that hardware can execute?

compilers

Whats the order of below your program?

applications software → systems software → hardware

What are the electrical signals?

1 and 0 (on and off)

What is an assembler?

a program for converting instructions written in low-level symbolic code into machine code

What is an example of an assembler?

programmer writes add A,B and it would translate to 100011001010000

What is assembly language?

a low-level, human-readable programming language that provides a symbolic way to write machine code

what is machine language?

language the machine understands

What is binary language?

the fundamental, low-level language of computers, consisting solely of the digits 0 and 1

What does assembly language require of the programmer?

to write one line for every instruction that the computer will follow, forcing programmer to think like computer

What are the three things that high-lvl programming languages offer?

-Allow programmer to think in a more natural language

-improved programmer productivity

-allow programs to be independent of computer on which they were developed

What does hardwares basic functions?

-inputting

-outputting

-processing

-storing data

capacitive sensing

a non-contact technology that detects changes in capacitance to sense the presence and proximity of objects or substances, including human touch, by measuring the disruption of an emitted electrical field.

What is a processor?

active part of computer following the instructions of a program to the letter

what is a datapath

performs arithmetic operations and control tells the datapath, memory, and IO devices what to do according to wishes of instructions of program

Where is the programs stored when they are running and also the data needed by running the program?

the memory

what is DRAM?

dynamic random access memory

What is a cache?

small, fast memory that acts like a buffer for DRAM memory

how is cache built?

using a different memory technology, static random access memory (SRAM) which is faster but less dense and more expensive than DRAM

how doees software communicate to hardware?

vocabulary

the words of vocabulary are called?

instructions

the vocabulary itself is called?

instruction set architecture or simply architecture of computer

The memory inside a computer is ____ ,when it loses power it forgets

volatile

The voltile memory used to hold data and programs they are running is the ____ ____ (primary memory)

main memory

The nonvolatile memory used to store data and programs between runs is the ____ ____

secondary memory

DRAMS have dominated main memory, while magnetic disks are _____ ____ _____

dominated secondary memory

Mobile devices use what kind of memory?

flash

Flash memory recap

Slower than DRAM, cheaper than DRAM, nonvolatile, costs moer per bit than disks, smaller, more rugged, more power efficient than disks

What interconnects whole computers allowing computer users to extend the power of computing by including communication

networks

Network computers have several advantages such as:

-communication

-resource sharing

-non local access

What is the most popular type of network?

ethernet

The ethernet is a what kind of area network?

local

Wide area networks cross ____ and are the backbone of internet which supports the web

continents