<< Chapter < Page Chapter >> Page >

General background information

An overview of computer programming

I recognize that some of you may not be ready for the kind of technical detail that I will provide in this section. If so, feel free to skipahead to the section titled Preview of the Scratch program . Just remember that this material is here waiting for you to come back and studyit when you are ready.

Not especially difficult

Computer programming is not especially difficult. However, it does require an aptitude for solving problems. In fact, a computer program is usually a modelfor a solution to someone's problem.

One step at a time

If you can learn to program a Digital Video Recorder (DVR), you can probably also learn to program a computer. Of course, a computer is more complicated than a DVR, so there is moreto learn. The important thing is to take the learning process in deliberate steps making certain that you understand each step before moving on to the nextone.

The hard work is often done for us

Fortunately, when we write programs using a high-level programming language such as Scratch, much of the hard work is done for us behind thescenes. For example, we don't have to perform the small incremental steps that are required to divide one number by another number.

As programmers, we are more like conductors than musicians. The various partsof the computer represent the musicians. We tell them what to play, and when to play it, and if we do our job well, we produce a solution to someone's problem.


All computers contain memory of one type or another. When we speak of human memory, we are usually speaking of the things that the human remembers.However, when we speak of computer memory, we are usually speaking of physical devices where data is stored for later retrieval. Most modern computers containmemory of a type that is often referred to as RAM (more on RAM later) .

All data is stored in a computer as numeric values. Computer programs do what they do by executing a series of operations on the numeric data.

Numeric data Even the text in this module is stored as numeric data in your computer. For example, theupper-case character "A" is commonly represented by the numeric value 65.

The operations that are performed on the numeric data generally consist of calculations and comparisons. It is the order and the pattern of those operations that distinguishes one computerprogram from another.

Random access versus sequential memory

The reason the memory in most modern computers is called random access memory (RAM) is that it can be accessed in any order. Some types of memory, such as a magnetic tape, can only be accessed in sequential order. (Yes, I did use computers with magnetic tape memory in my younger days during the sixties andseventies.)

Sequential access means that to get a piece of data that is stored deep inside the memory, it is necessary to start at the beginning and examine every piece of data until the correct one is found. Thisis typically a slow process.

Combination random/sequential memory

Other types of memory, such as disks provide a combination of sequential and random access. For example, the data on a disk is stored in tracks that formconcentric circles on the disk. The individual tracks can be accessed in random order, but the data within a track must be accessed sequentially starting at aspecific point on the track. While faster than magnetic tape, even this process is usually slower than true random access memory.

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
yes that's correct
I think
Nasa has use it in the 60's, copper as water purification in the moon travel.
nanocopper obvius
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
analytical skills graphene is prepared to kill any type viruses .
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Teaching beginners to code. OpenStax CNX. May 27, 2013 Download for free at http://cnx.org/content/col11498/1.20
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Teaching beginners to code' conversation and receive update notifications?