Install CMake in Ubuntu 18.04

CMake is a cross-platform free and open-source software application. Cmake is used to manage the build process of software in compiler-independent method. I am using this software to build VTK and ITK.

Installation Steps :

First of all type
sudo apt update

Then go to https://cmake.org/ website and select the download tab. Next select binary distribution and download Linux x86_64 and then download. Following 3 images shown that.

 run following command to making the file readable, writable and executable by everyone.
chmod +777 cmake-3.13.0-rc3-Linux-x86_64.sh

you can see the color difference before and after this command runs.

Before

After

Then start installation using following command

./cmake-3.13.0-rc3-Linux-x86_64.sh

Read the details and Accept the license

 Again press Y when this dialog appears

Eclips Installation in Ubuntu 18.04

Eclipse is an integrated development environment used in computer programming.

So in this article we are presenting how to install eclipse for your Ubuntu 18.04 operating system.

Steps : 

first type and run the update command

sudo apt update

then check your installed Java version

so in my computer java is not installed. Therefore Terminal gives us an options to install Java.

Therefore I have installed Java using following command.
 sudo apt install default-jre

Then type the following command to install Eclipse

After installation you can open the Eclipse IDE

 

you need to assign a workplace location. I selected the default position.

 

Eclipse IDE looks like this

How to Upgrade Ubuntu 16.04 to Ubuntu 18.04

I have used Ubuntu 16.04 LTS nearly 2 years. It worked well. But as a normal human being I got an idea to upgrade Ubuntu 16.04 LTS to Ubuntu 18.04 LTS. My laptop is an old one. That is Compaq Presario CQ62 laptop with core i-3 processor. Therefore first of all I checked the minimum hardware requirements for Ubuntu 18.04 LTS.  According to Ubuntu site and Google, minimum requirements are follows.

    • 2 GHz Dual Core Processor
    • 2 GB RAM (System Memory)
    • Minimum 25 GB Hard Drive space
    • VGA Capable of 1024 x 768 screen resolution
    • CD/DVD Drive or USB port for installation

My machine is up to minimum system requirements. But my CD/DVD drive is not working. But I have 3 working USB ports. Therefore I decided to upgrade my Ubuntu 16.04 to 18.04.

My machine is up to minimum system requirements. But my CD/DVD drive is not working. But I have 3 working USB ports. Therefore I decided to upgrade my Ubuntu 16.04 to 18.04.

Steps :

• First run the sudo apt update command for update the Ubuntu 16.04 system update

• Then run the sudo apt upgrade command for Ubuntu 16.04 system upgrade.

• Then run the sudo apt dist-upgrade command.

 

• Then run the sudo apt autoremove command.

 

• Select Y, when following question appears

• So, finally run the following commands for upgrade Ubuntu 16.04 to Ubuntu 18.04 operating system.

After install upgrades machine restarts and Ubuntu 18.04 desktop appears.

Memory system

Basically divided to 2 main categories

• Internal memory – RAM,ROM,CACHE
• External memory – Hard Disk, CD/DVD, Magnetic Tape, USB Flash

The main characteristic of memory is its capacity. Internal memory capacity is typically expressed in terms of bytes or words. Common word lengths are 8-bit, 16-bit and 32-bits. External memory capacity is typically expressed in terms of bytes.

• Word – the natural unit of organization of memory. The size of the word is typically equal to the number of bits used to represent a number.
• Addressable units – word or byte.
• Unit of transfer – number of bits read out of or written in to memory at a time.


We can divide memory systems based on method of accessing. There are

• Sequential Access – access made in a specific linear sequence. A shared read/write mechanism is used.
• Direct Access – individual blocks or records have a unique address based on physical location. Access is accomplished by direct access followed by sequential access. Shared read/write mechanism is used.
• Random Access – each addressable location in memory has a unique. Physically wired in addressing mechanism.
• Associative Access – a random access type memory that enables one to make a comparison of desired bit locations within a word for specified match, and to do this for all words simultaneously. Thus a word is retrieved based on a portion of contents rather than its address.

Performance parameters

• Access time (Latency) – time taken to perform a read/write operation.
• Memory cycle time – access time plus any additional time required before a second access can commence (applicable to RAM)
• Transfer time – rate at which data can be transferred into or out of memory unit.

For RAM = 1/ (cycle time)

Non RAM TN = TA + N/R

TN = average time to read or write N bits
TA = average access time
N = number of bits
R = transfer rate in bits per second

Physical characteristics

• Volatile memory
Information decays naturally or is lost when electrical power is switched off
• Non volatile memory
Information one recorded remains without deterioration until deliberately change. No electrical power is needed to retain information.

Memory hierarchy

Key characteristics of memory
• Cost
• Capacity
• Access time

 Faster access time, greater cost per bit.
 Greater capacity, smaller cost per bit.
 Greater capacity, slower access time.





Decreasing cost per bit
Increasing capacity
Increasing access time
Decreasing frequency of access of the memory by the processor.

RAM (RANDOM ACCESS MEMORY)

A memory unit stores binary information in groups of bits called words. It is an one unit. A group of 8-bits is called a byte.
1 byte = 8-bit word





Ex: memory unit 1k words of 16-bit each.
1k = 1024 = 210
16-bits = 2 bytes
Memory 2048 = 2k bytes





Relationship between words and address bits
2k≥m
m = total number of words
k = number of address bits

Types of memories

The mode of access of a memory system is determined by the type of components used.

SRAM (Static RAM)

Consists essentially of internal latches that store the binary information. The stored information remains valid as long as power is applied to the unit.

DRAM (Dynamic RAM)

Stores the binary information in the form of electric charges on capacitors. The capacitors are provided inside in the chip by MOS transistors. Capacitors must be periodically recharged by refreshing the dynamic memory.

SRAM vs. DRAM

DRAM
• Reduced power consumption
• Larger storage capacity in a single memory chip
• Less expensive
• Used for Main Memory
SRAM
• Easier to use
• Has shorter read/write cycle (Faster than DRAM)
• Used for Cache Memory

Internal construction

The internal construction of RAM of m words and n bits per word consists of m×n binary storage cells.









Select bit = ‘1’ – read
‘0’ – write




RAM

Coincident decoding

Basic idea in 2-Dimensional decoding is to arrange the memory cells in an array that is close as possible to square.