Google's Project Ara

Project Ara is the codename for an initiative by Google that aims to develop an open hardware platform for creating highly modular smartphones. The platform will include a structural frame (endoskeleton that holds smartphone modules of the owner's choice), such as a display, camera or an extra battery. It would allow users to swap out malfunctioning modules or upgrade individual modules as innovations emerge, providing longer lifetime cycles for the handset, and potentially reducing electronic waste. A market pilot for Project Ara is scheduled for early 2015 with a target bill of materials cost of $50 for a basic grey phone.  The project was originally headed by the Advanced Technologies and Projects team within Motorola Mobility while it was a subsidiary of Google. Although Google had sold Motorola to Lenovo, it is retaining the project team who will work under the direction of the Android division.

Project Ara

Project Ara smartphones are composed of modules assembled into metal frames
Developer	Google, Motorola, Linaro
Manufacturer	User
Product family	yes
Type	Modular smartphone
Release date	6th feb, 2015
Retail availability	up to 7 years
Introductory price	minimal cost ~US$50
Operating system	Android
Power	modular battery
System-on-chipused	Toshiba-supplied for the first year
Website	Project Ara Project Ara Forum

Structure and features

Ara frames

Frame	Size	Rear module slots
Mini	45 × 118 × 9.7 mm	2 × 5
Medium	68 × 141 × 9.7 mm	3 × 6
Large	91 × 164 × 9.7 mm	4 × 7

Ara Smartphones are built using modules inserted into metal endoskeletal frames known as "endos". The frame will be the only component in an Ara Smartphone made by Google. It acts as the switch to the on-device network linking all the modules together. Two frame sizes will available at first: "mini", a frame about the size of a Nokia 3310 and "medium", about the size of a LG Nexus 5. In the future, a "large" frame about the size of a Samsung Galaxy Note 3 will be available. Frames have slots on the front for the display and other modules. On the back are additional slots for modules. Each frame is expected to cost around US$15. The data from the modules can be transferred at up to 10gigabits/sec per connection. The 2×2 modules have two connections and will allow up to 20gigabits/sec. This is to defer its obsolescence as long as possible.

Modules can provide common smartphone features, such as cameras and speakers, but can also provide more specialized features, such as medical devices, receipt printers, laser pointers, pico projectors, night vision sensors, or game controller buttons. Each slot on the frame will accept any module of the correct size. The front slots are of various heights and take up the whole width of the frame. The rear slots come in standard sizes of 1×1, 1×2 and 2×2. Modules can be hot-swapped without turning the phone off. The frame also includes a small backup battery so the main battery can be hot-swapped.  Modules are secured withelectropermanent magnets. The enclosures of the modules were planned to be 3D-printed, but due to the lack of development in the technology Google opted instead for a customizable molded case. 

Modules will be available both at an official Google store and at third-party stores. Ara Smartphones will only accept official modules by default, but users can change a software setting to enable unofficial modules. This is similar to how Android handles app installations.

C++ code to print diamond (size = even no)

#include<iostream>
using namespace std;
void main()
{
int size,newsize,n,p,controller,size2;
cout<<"Enter size any even number";
cin>>size;
n=size/2;
p=size-2;
size2=0;
controller=size-p;
for(int i=0;i<n;i++)
{
newsize=n-i;
for(int j=1;j<newsize;j++)
{
cout<<" ";
}
for(int k=1;k<=controller;k++)
{
cout<<"*";
}
if(p>0)
p=p-2;
controller=size-p;
cout<<endl;
}
p=size-2;
n=size/2;
for(int l=1;l<n;l++)
{
size2=n-l;
for(int m=size2;m<n;m++)
{
cout<<" ";
}

for(int c=1;c<=p;c++)
{
cout<<"*";
}
p=p-2;
cout<<endl;

}
}

Classification of Computer Languages

Classification of computer languages:

• Machine Level Language.
• Assembly Level Language.
• High Level Language.

MACHINE LANGUAGE:  The most elementary and first type of computer, which was invented, was machine language.

•  Machine language was machine dependent.
•  A program written in machine language cannot be run on another type of computer without significant alterations. 
• Machine language is some times also referred as the binary language i-e, the language of 0 and 1 where 0 stands for the absence of electric pulse and i stands for the presence of electric pulse. 
• Very few computer programs are actually written in machine language.

ADVANTAGE:

• Can be executed very fast.

LIMITATIONS:

• Machine Dependent.
• Difficult to program.
• Difficult to modify.

ASSEMBLY LANGUAGE: As computer became more popular, it became quite apparent that machine language programming was simply too slow slow tedious for most programmers. 

• Assembly languages are also called as low level language instead of using the  string of members programmers began using English like abbreviation to represent the elementary operation. 
• The language provided an opportunity to the programmers to use English like words that were called MNEMONICS.

ADVANTAGES:

• Easier to understand use.
• Easier to locate and correct errors.
• Easier to modify.
• No worry about addresses.
• Easily relocatable.
• Efficiency of machine language.

LIMITATIONS:

• Machine dependent.
• Knowledge of hardware required.
• Machine level coding.

HIGH LEVEL LANGUAGE:  The assembly languages started using English like words,m but still it was difficult to learn these languages. 

• High level languages are the computer language in which it is much easier to write a program than the low level language.
•  A program written in high level language is just like gibing instruction to person in daily life. 
• It was in 1957 that a high level language called FORTRAN was developed by IBM which was specially developed for scientist and engineers other high level languages are COBOL which is widely used for business data processing task.
• BASIC language which is developed for the beginners in general purpose programming language. you Can use C language for almost any programming task. 
• PASCAL are other high level languages which has gained widespread acceptance.

ADVANTAGES:

• Machine independent.
• Easier to learn and use.
• Fewer errors during program development.
• Lower program preparation cost.
• Better documentation.
• Easier to maintain.

LIMITATIONS:

• Lower execution efficiency.
• Less flexibility to control the computer's CPU, memory and registers

Secondary Storage Devices

Secondary storage is preferred over primary storage due to the limited capacity and votality of primary storage.
SEQUENTIAL AND DIRECT ACCESS DEVICES:

 SEQUENTIAL ACCESS STORAGE DEVICE:
 A sequential access storage device is one in which arrival at a desired storage location is preceded by sequencing through other locations so that access time varies according to location.
Magnetic Tape is an example of sequential access storage device.

DIRECT ACCESS STORAGE DEVICE:
A direct access storage device is one in which we can reach and access any storage location at random, and  approximately equal access time is required for accessing each location.
Magnetic disks,Optical disks and memory storage devices are examples of direct access storage device.

Magnetic media

Magnetic media stores data by assigning a magnetic charge to metal. This metal is then processed by a read head, which converts the charges into ones and zeros. Historically, magnetic media has been very popular for storing programs, data, and making backups. It looks set to continue in this role for some time. However, solid state technology is starting to be used more and more, storing programs and data on new devices such as mobile phones and cameras.

Magnetic media
Device	Size
Hard Disk	Up to 4 Terabytes
Magnetic Tape	Up to 2 Terabytes

Hard disk

Hard disks are usually found inside computers to store programs and data. They are increasingly cheap and more and more companies are using them to back things up. Hard disks can vary in physical size with some disks getting as small as your thumb. The capacity of a commercial disk is currently up to about 4 terabytes allowing users to read and write to them.

Magnetic Tape drive

Increasingly obsolete, the tape has been a medium to deliver software and back up data since the early days of computing. Nowadays they are used mostly for corporate backing up and archiving of data. Tapes are sequential data stores, meaning that if you had information stored at the end of the tape you would have to wind your way through the entirety of the tape before you could read it. There is no random access like with a hard disk! Tapes can be several terabytes in size and reading and writing can be very fast as long as you read or write continuous sections of the tape at once. It is

Fast

High capacity

Cheap per megabyte

Optical media

Optical media works by creating a disc with a pitted metallic surface. There are several different types of disk out there ranging from 650 MB to 128 GB, with the pits and lands getting closer together for higher volume disks. The principle behind how each of them works is the same.

pitted surface visible on the surface of a CD. Massively zoomed in!

Optical media
Device	Type	Size	Image
CD-ROM CD-R CD-RW	Read Only Write once then Read only re-Writable	650 - 900 MB
DVD-ROM DVD-R DVD-RW DVD-RAM	Read Only Write once then Read only re-Writable re-Writable	4.7 - 9.4 GB
Blu-ray (BD) disc HD DVD (obsolete)	Re-Writable and Read Only versions available. Uses a blue laser, that is able to recognise smaller pits and lands, which allows for the pits and lands to be more closely packed, and so store more data	25 - 128 GB

Solid-state memory

Solid-state memory
Device	Description
USB flash drive	Up to 256 GB
Memory card	Up to 256 GB

USB (memory stick) Flash Drive

Internals of a typical USB flash drive
1	USB Standard-A plug
2	USB mass storage controller device
3	Test points
4	Flash memory chip
5	Crystal oscillator
6	LED
7	Write-protect switch (Optional)
8	Space for second flash memory chip

USB Flash drives are solid state, that means that there are no moving parts. This is very useful for seek times as we don't have to wait for mechanical movement, meaning seek time is very low and it allows for fast Random Access Memory. Flash drives can be set to read only mode, but they will always allow for reading and writing. The size of flash drives is not as great as a Hard Disk and they are generally much more expensive per megabyte

1. put drive into USB socket
2. USB driver loads, providing the computer with code on how to read and write from the USB
3. The USB is read, giving information on the file and folder structure (File Allocation Table) to the Computer
4. [Reading] The user chooses to open a file, the Computer sends the address wanted to the USB port
5. [Reading] The USB returns the data at the location requested
6. [Writing] The computer sends data to the USB port where it is place into empty space on the drive
7. [Writing] The computer then requests a new version of the file and folder structure

Advantages:

Very fast seek times

Very portable

Limitations:

 Limited capacity

 Expensive per MB when compared to Hard Disks

Memory cards

Work in much the same way as a Flash drive and can often be converted into Flash Drives. They have different connectors and are generally smaller than USB Flash drives allowing for them to be used in cameras, mobile phones and game consoles.

.

Printer And Its Types.

 PRINTER is the most popular output device used today to produce hard copy output. There are many types of printers which are used by the users as according to their need. These are very useful nowadays as all the things which are uneasy to read on the monitor screen we used to print those things and read carefully. Below we describe the various types of Printers.

Dot-Matrix Printer

It is a character printer that print one character at a time. This Printer can form characters and all kinds of images as pattern of dots. Since dot matrix printer produce printed output as pattern of dots, they can print any shape of character that a program can describe. They therefore, can print many special characters, different sizes of print, and also have the ability to print graphics such as charts and graphs.

Dot Matrix printer are normally haves slow printing speeds ranging from 30-600 characters per second. They are available at very low cost. These types of printers are generally used to print the shipping invoices.

Inkjet Printers

It prints characters by spraying patterns of ink on the paper from a nozzle or jet that can heated up selectively. The ink comes out of the nozzle in a form of vapors. After passing through a reflecting plate, it forms the desired letter/shape at the desired place. It is also a Character printer but it produces high quality output than dot matrixprinters because these printers form characters with very tiny ink dots.

Inkjet printers are slower than dot matrix printer as inkjet printing speed is 40- 300 characters per second. Inkjetprinter is also more expensive than dot matrix because it produces the high quality prints with more transformed technology. These printers are very popular because they are less expensive than laser printers and can print faster and accurate than dot matrix and other impact printers.

Drum Printer

Drum printer is a line printers that print one line at a time. In addition the drum printer is also the impact printer. In this Printer it has a set of  hammers mounted in front of the drum in a manner that an inked ribbon and paper can be placed between the hammers and the drum. Than the drum rotates at a high speed. A character is printed at a desired print position.

This printer has the speed of 300- 2000 lines per minute. This printer also produces lots of noise that’s why cover is used to reduce the noise.

Chain Band Printer

Chain/Band printer are line printers that prints one line at a time. It consist of of a metallic chain/band on which all characters of the character set supported by the printer are embossed. A standard  character set may have 48,64 and 96 characters. The characters in the character set are embossed several times on the chain/band.

Unlike drum printer the chain/band printer can be changed easily. It allows the printing to be done in different fonts and styles in the same printer. Due to the impact printing chain/band printers are noisy in operation and often use a cover to reduce the noise level. Printing speeds of the chain/band printers range from 400 – 3000 lines per minute.

Laser Printers

Laser printers are the page printers that prints one page at a time. main component of the laser printer are a laser beam source, multi sided mirror a photoconductive drum, and toner. Laser printers produces high quality output because they form characters by very tiny ink particles. The high end laser printer can have a resolution of 1200 dpi. Due to the high resolution , these printers give excellent graphics art quality.

Laser printers are faster than other printers discussed earlier. Low speed laser printers can print 4 to 12 pages per minute. Owing to their better print quality and printing speed, laser printers are more expensive than the other types of the printers. These printers are very popular in the market because of its fast printing.

OS- Operating System.

OPERATING SYSTEM:

An operating system (OS) is software that manages computer hardware and software resources and provides common services for computer programs. The operating system is an essential component of the system software in a computer system. Application programs usually require an operating system to function.

For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and will frequently make a system call to an OS function or be interrupted by it. Operating systems can be found on almost any device that contains a computer—from cellular phones and video game consoles to supercomputers and web servers.
UNIX  OS:

• Developed in the early 1970s at Bell Laboratories by Ken Thompson and Dennis Ritchie.
• Written in C high level language hence highly portable.
• Multi-user, time sharing OS.
• Used on a variety of computers ranging from notebook computers to super computers.
• Especially prevalent on RISC workstations such as those from Sun Microsystems, IBM and Silicon graphics
• Structured in three layers- kernel,shell and utilities.

MS-DOS:

• Stands for Microsoft Disk Operating System.
• Single user OS for IBM and IBM compatible personal cmputers.
• Structured in three layers BIOS (Basic Input Output System), kerneel, and shell.
• Very popular in 1980's, now not in much use and development of Microsoft Windows OS in 1990s.

LINUX:

• Open-source OS enhanced and backed by thousand of programmer world wide.
• Multi-Tasking, multiprocessing OS, originally designed to be used in PCs.
• Several Linux distributions available (Red Hat,SuSE). Difference in distribution is mostly set of tools, number and quality of applications, documentation, support, and service.