The Four Generations of Computers

Images taken from Jaybirduk from flickr, click on the images to be taken to that page.

In TU100 I have learnt that there're 4 generations of computers, the first one being from around WW2 these are the computers which use thermionic valves, such as the Colossus which was used to break the codes by the germans.

This machine used paper tape  for data input, for the output it would send it to an electric typewriter.

The public did not know about this machine until it went on to the public domain in the 1970's, it is now an attraction at Bletchley Park, Milton Keynes, the original Colossus was decommissioned at the end of the war and dismantled and destroyed, but a working replica was produced which stands in its place today.

ENIAC (Electronic Numerical Integrator and Computer)Image taken from Click on the image to be taken to that page.

Another example of the first generation computers was the ENIAC (Electronic Numerical Integrator and Computer) this was built by the University of Pennsylvania this also used thermionic valves the same as Colossus. This computer weighed 27 tonnes and occupied 63 square metres and was 26 metres long.

It was used to for lengthy calculations for the US Military. The ENIAC was not very user friendly like computers are today it used to take weeks and weeks to set up a program and errors could occur and then you would have to start again. You could not save your program state either and it was very unreliable, it was under repair more than it was working.

On a side note, Thermionic valves were very delicate and used to break a lot, they discovered that if you left the machine on then the valves would last longer.

IBM 608 calculator. This image was taken from

The Second generation of computers were those that used transistors, these came out in the late 1950's. These computers where still very large and still very expensive for example one of the first computers that had this transistor technology was IBM's 608 at a price of $83,000 that was a huge outlay for most companies. Most of the computers of course as I mentioned above they were large but a lot smaller than the Colossus and the ENIAC, some of these transistor based computers were about the size of wardrobes.

These new transistors were a few millimetres in diameter so they were less than a thousandth of the volume of the thermionic valve. Transistors were much cheaper to manufacture than valves and of course they were more reliable as well. the switching speeds were also much faster than that of the valves.

The third generation of computers saw rise of the integrated circuit (IC) this was also known as 'chip' or 'silicon

IBM System/360

chip' with these computers punchcards and tape were the thing of the past they were no longer used for input and output instead they had peripherals known as 'keyboards' for the input and for the output they had 'monitors' so for the out put of data they no longer needed paper printouts, also in this generation the Floppy disk was introduced, The IC was much faster in terms of processing speed than any of it's predecessors. Many minicomputers and mainframes moved onto this technology. These silicon chips were made from several components integrated onto a single chip. The IC computers were also able to talk to each other through telephone lines these were called terminals and could be distributed across the country and connected to a single shares computer.

The fourth generation of computers are basically the computers of today - the microprocessor (CPU) all computers and devices including Smart phones, tablets laptops, set top boxes, and even televisions have microprocessors, the microprocessor came out in the late 1970's, it has reduced running costs and manufacturers are able to make in large numbers. With the rise to the microprocessor, home computers were very much a reality, as these processors were cheaper to make and as I said before companies to make large amounts of them every day people started to have a personal PC in their home.

A IBM XT from the early 1980's image taken from









A new chapter in my life, a new beginning, an exciting and challenging time for me, as I embark on an academic journey with the OU.

I have enrolled on my first Module, studying for a BSc in Computing and IT, I am really excited but at the same time nervous. I haven't studied for over 20 years and I am probably going to find this a struggle.

I have decided that I want a better career with better prospects, and I know that I will be able to do it with determination and a drive to succeed. smile


This is a personal blog for my OU studies.

Here I will document what I have learnt, well as much as possible, or stuff I feel I need to explain to further my understanding of it. If I was to put everything down in this personal blog then I would not have any time to do anything else that is important in my life.


The First Module I am going to be doing is My Digital Life which is 60 Credits, the course work includes,

  • 6 Tutor-marked assignments (TMA's)
  • 7 Interactive computer-marked assignments (iCMA's)
  • no examination (thanks goodness!)
  • No residential school

This module is split into 6 study blocks.

Block 1: Myself

Starting with our own activities in consuming, processing and publishing information, you’ll learn the basic concepts of data and information. You will move on to look at the underlying structure of the internet and the software that interacts with it. You’ll also create simple web pages, and learn some basic programming skills.

"I am really looking forward to starting this module, it looks really interesting and will hopefully give me the foundation I need to move forward with my study, I've always wanted to learn to write websites and to be able to do programming, albeit basic programming." James Fox

Block 2: My Stuff

You’ll investigate the development of the hardware and software at the heart of the many everyday devices that contain a computer, from smart meters to cars. You’ll be introduced to the skills you will need to interpret data, and you’ll learn how to find, assess and discuss material on the Web and elsewhere.

"I have always been interested in computer hardware and how it all comes together, I have always built my own computers, until recently when I have bought my iMac. I can't wait to learn more about the software as well, it will be really interesting" James  Fox

Block 3: My Place

Computing power is present in a wide range of everyday objects and environments, from mobile phones and satellite navigation devices to health monitoring and central heating systems. Using examples from these areas, you will see how large- and small-scale networks are used to link devices and allow information to flow between individuals, networks and countries.

"I am really looking forward to this block, I am really interested in computer networking and will be interested to learn more about it, I run - like most people nowadays a small hime network, I did, at one point have a domain controller which was the main server in my house, I have down sized the network and just have one server running which is used for my Media, photos and now my OU Studies" James Fox

Block 4: My Friends

You’ll study the social aspects of computer technology, looking at how we communicate using social networking, real-time chat, forums, virtual worlds and computer games. You will learn how to create and share audio-visual content, and how the skills you are developing –working and communicating with others online – can be of value in the workplace.

"I am always on the net, whether it be chatting online with my friends, Using Facebook, Google, or Whats App - to watching youtube, online gaming and research so I will be really interested with this block as studying the social aspects of computer technology is no key to everyone's everyday life, most people in the world have access to Facebook or google or other types of online social media" James Fox

Block 5: My Society

You will study how the growth of the electronic society affects us all, positively and negatively, using five perspectives – governmental, individual, technical, commercial and ethical. You’ll use case studies that focus on the legal and ethical aspects of a digital life, such as encryption and copyright. You will learn how to form arguments from conflicting evidence and produce your own researched opinion on a controversial topic.

"I think I may struggle with this one, I will find it interesting and engaging but I have never had do research on this scale before, I'm sure it wont be as daunting as I think it is right now when it comes to doing this block, I will see!" James Fox 

Block 6: My World

This final block will draw together the various themes you have studied so far and use them to look at how the world is rapidly changing, as computing technologies are being developed and applied. Using several case studies, you will examine the implications of the 'digital divide', and how it might be overcome.

Throughout your study of the module you will develop a wide range of skills that you will need for higher-level study. This includes programming via a purpose-built graphical programming environment. You will use this environment to control the SenseBoard hardware included in the module materials.

The study material is available online, with some also provided in print and some on DVD. The module is also available in several ebook formats for offline use on desktop computers, ebook readers, and mobile devices. You will be able to study much of the module on mobile devices, but some of it will require a desktop or laptop computer.

"This final block, I think will be the one that shows me how much I have learnt over the past year. I am looking forward to programming via the purpose-built graphical programming environment. Examining the implications  of the digital divide. I would hope that it will be really interesting and engaging. Computers change all the time and who knows where it will go in the future, I'm thinking proper house hold robots which makes us humans really lazy!" James Fox

Personal Note from me

I am hoping to make a few friends on my journey so if anyone who has actually read this to the end - Thank you  but most importantly if you are doing the same course as me then maybe we could buddy up at some point to give each other support and guidance.   James Fox