Computer Architecture on maladroit.dev

Assembler

Mon, 01 Jan 0001 00:00:00 +0000

A translator of symbolic version of an instruction to binary. Assembly language is an example of a symbolic language and machine language is a binary language.

References

Computer Organization and Design

Binary

Mon, 01 Jan 0001 00:00:00 +0000

Binary is a base 2 number system that is used in machine code. It can be handy at times to transform data to binary or to preform bit-wise operations.

Corner cases

Negative numbers
Overflow/underflow errors

Bit-wise operations

Check if k’th bit is set

var num uint
num & (1 << k) != 0

Set the k’th bit

var num uint
num |= (1 << k)

Clear the k’th bit

var num uint
num &= ^(1 << k)

Toggle the k’th bit

var num uint
num ^= (1 << k)

Multiply by 2^k

var num uint
num << k

Divide by 2^k

var num uint
num >> k

Check if power of 2

var num uint
(num & (num - 1)) == 0

Swap two variables

var num1 uint
var num2 uint
num1 ^= num2
num2 ^= num1
num1 ^= num2

References

Tech-Interview-Handbook

Compiler

Mon, 01 Jan 0001 00:00:00 +0000

A translator of some programming language to instructions that the hardware can execute.

References

Computer-Organization-and-Design

Control

Mon, 01 Jan 0001 00:00:00 +0000

The control commands the Datapath, Memory, Input and Output devices using the programming instructions given to it

References

Computer Organization and Design

CPU

Mon, 01 Jan 0001 00:00:00 +0000

The central processing unit (CPU) is the active part of a computer that is made up of the Datapath and Control

CPU execution time

CPU execution time is the time spent by the processor to complete a task

User CPU time

The time spent on the program itself

System CPU time

The time spent in the operating system on behalf of a program

References

Computer Organization and Design

Datapath

Mon, 01 Jan 0001 00:00:00 +0000

The datapath handles arithmetic operations

References

Computer Organization and Design

Input

Mon, 01 Jan 0001 00:00:00 +0000

References

Computer Organization and Design

Memory

Mon, 01 Jan 0001 00:00:00 +0000

The storage area where programs exist when they are running. It is also where data is kept that is needed by running programs.

References

Computer Organization and Design

Operating system

Mon, 01 Jan 0001 00:00:00 +0000

An operating system is an interface between a program and the hardware. It handles input and output operations for the computer and allocates storage and memory.

References

Computer-Organization-and-Design

Output

Mon, 01 Jan 0001 00:00:00 +0000

References

Computer Organization and Design

RAM Model of Computing

Mon, 01 Jan 0001 00:00:00 +0000

The RAM Model of Computation is a model for measuring time by counting the number of steps an algorithm must take to complete. There are some assumptions made in the RAM Model such as:

All simple operations are considered to be 1 step
Loops and subroutines count for N steps with N being the number of iterations
Memory access takes 1 step

Another crucial part of the RAM Model is analyzing algorithms in multiple scenarios. The RAM Model considers:

Standard streams

Mon, 01 Jan 0001 00:00:00 +0000

Standard in, out, and error streams created when a command is run. They are usefully for passing data between applications. Most CLI applications support using stdin as in input and will create both stdout and stderr outputs, allowing multiple commands to be chained together.

The streams behave like files and are given the following descriptors:

stdin: 0
stdout: 1
stderr: 2

These streams can be redirected using > or >> where > overwrites the file and >> appends to the end. To redirect a specific stream, prepend the operators with the stream descriptor.

Systems software

Mon, 01 Jan 0001 00:00:00 +0000

Systems software is software that sits between the hardware and application software of a computer. The two central types are the Operating-system and Kernel

references

computer-organization-and-design