Microplop » Andy Callaghan

Conjoined twins fail

Andy Callaghan — Mon, 18 May 2009 22:22:13 +0000

Just made this…

Hope you like it!

Why did we start at IPv4? What happened to IPv5?

Andy Callaghan — Wed, 29 Apr 2009 16:24:17 +0000

On looking at the various protocols in network communication, the most puzzling version numbering is with IPv4 to IPv6 without version 5, 3, 2 or 1. Most people believe that IPv5, 3, 2 or 1 were not even developed, but this is not true. This article aims to clarify the history of IP and answering potentially difficult about the version numbers.

Why did we start at IPv4?

When the internet was known as ARPANET – a US government research project, the TCP protocol had a lot more functionality than what we are now used to. The research scientists that developed TCP were designing it for not only host-level point-to-point transmission but also for encapsulation and routing across the ARPANET network. After the scientists realised that they were using the one protocol for too much work on the network, they decided to fork the encapsulation and routing to another protocol called the Internet Protocol, IP. But by this time, the researchers had done enough work on this protocol for it to be deemed in its third version, so was informally known as IPv3. After the full TCP/IP stack had been fully developed as we now know it, further work had been completed on IP and so was called IPv4.

What happened to IPv5 then?

Soon after this, IPv4 was standardised by the IETF. Many different scientists and professionals alike noted that IPv4 would not scale well as it was in the future, and so in the 1970s work on the next version of IP was started, the Internet Stream Protocol (ST). The ST protocol was designed to be the connection-oriented complement to IPv4 and used the same link-layer framing as IPv4. ST used the same addressing scheme as IP and was always intended to run concurrently with IPv4. The researchers were attempting to ue a connection-oriented IP so that real-time internet applications such as VoIP, multiplayer gaming etc. will have more latency garuantees and be generally more reliable than IPv4.

The development of IPv6

ST was considered a great advance at the time against IPv4, but at the same time as ST was being developed, so was IP next generation (IPng). IPng was developed in 1994 and was aware of the dwindling address space offered by both IPv4 and IPv5/ST, and so used a 128-bit addresses for destination and source which offers a much broader availability of addresses. The IPng protocol was therefore seen as future proof in the eyes of research scientists and the industry in terms of solving the IPv4 addressing problem, so IPng was adopted as the next defacto standard of IP. IPng was given the version number IPv6, as a direct future replacement for IPv4 in the RFC in 1996.

Post taken in part from CS revision Wiki at Microplop.com.

Steps to learn Ruby on Rails

Andy Callaghan — Sun, 12 Apr 2009 21:16:41 +0000

I have pretty sucessfully taught myself Ruby on Rails from scratch with no real help from any one resource or book – in this post I will show you in some steps on how to learn the basics of Ruby on Rails, as well as some of the more detailed and difficult concepts to grasp.

In this post I will assume that you have already programmed in an interpreted or compiled language – C++, Java, Perl, Python are all perfect starts to a programming career.

Make sure you read all of this article before you begin, so you can see how your Rails skills will develop.

Start hacking

This is how all good programmers begin: with a weekend of time and an old fashioned hack-a-thon. I personally started with building a simple recipe app with collections of recipes in according to ingredients etc…

Install Ruby, Rails and Gems and get them working
If you’re on Windows, you need a Linux virtual machine to do your development in. You’ll have A LOT of problems with Rails’ incompatibilities with Windows. Just do it, trust me!
Make the simple ‘Hello World’ app.
Hack away.

It is up to you this stage however.

Buy a few decent books

It’s all good me saying “Just get stuck in”, but I did need a lot of physical textual help with my learning curve of Ruby on Rails more complex areas. Not all the books that I bought were helpful or even in date, but there was a few that I found were invaluable to my learning.

Book one: Advanced Rails Recipes

Book two: RailsSpace

Book three: Rails Recipes

Subscribe to Railscasts

Ryan Bates presents a weekly video podcast in all areas of Rails. The later episodes tend toward more advanced areas of Rails, but if you get all of the episodes, you will find it difficult to get stuck with development in Rails.
www.railscasts.com

Terrorism record fail

Andy Callaghan — Fri, 16 Jan 2009 03:53:18 +0000

User is asked whether they would like to beat a record for the most casualties in a terrorist act.

iPod space fail

Andy Callaghan — Fri, 16 Jan 2009 00:57:50 +0000

The remaining free space on an iPod is reported to be greater than the actual size of the drive itself.

Zavvi fail

Andy Callaghan — Fri, 16 Jan 2009 00:41:01 +0000

I really see the mark down in the price of guitar hero here...

During all of this recent global economic kerfuffle one of the more recent retail closures in the UK has been music and games retailer Zavvi. I went in today and took the above picture of their so called ‘Closing down sale’…

Welcome back, Wordpress

Andy Callaghan — Mon, 22 Dec 2008 23:43:24 +0000

Well… after a little (make that a lot) tinkering and attempting to make Rails work on Mediatemple.net, I have decided to run all the way back home to Wordpress for my blogging platform of choice!

No more Rails for blogging here at least, but that’s not to say I don’t really really enjoy programming in Rails, I just think that Wp has a lot more to offer than what I can cook-up in Rails with the time I have!

Computer Science wiki for Revision now up!

Andy Callaghan — Mon, 28 Apr 2008 15:34:11 +0000

Yes revision has begun, and I had a novel and possibly unique idea in regards to a wiki – I could use it to formalise my revision work, by slowly adding my work up as a wiki.

Okay. Maybe it’s not too unique then, but it sure as hell is helping me revise.

Anyway, the link is here and at the top left of the layout on this page.

Computer Science at Microplop.com

A while has passed

Andy Callaghan — Mon, 24 Mar 2008 01:53:33 +0000

Here’s the thing… I’ve been busy of late, very busy.Â

Unfortunately, this blog has suffered because of it! Anyway, rant over!

Another thing… I didn’t get past the second interview with Google (yeah, I may as well use names now!). They didn’t attribute this decision to my phone interviews – I had performed well at this stage I was told, but instead it was my work experience that brought me down.Â

The second phone interview was much harder than the first. The first was really just to make sure that I was breathing and not a complete idiot. However the second interviewer asked a question every minute, and were all like as such:

Â - Why did Google buy Google Earth?

Â - What would you do with 5,000 computers and 5 paid engineers?

Personally, I’m not that this is the actual reason. I have plenty of experience in the IT workplace, andÂ definitely more than than most of the peers on my course. SO! I think it was more down to my lack of age, rather than experience.

Despite all of this, Eli Lilly have very nicely kept my pending job for my as a Technical Analyst at Erl Wood. Today I had a familiarisation day which went well, and have given me a lot more confidence in what I’ll actually be doing there!

My exams start next week, but I will hopefully post a bit more frequently that once every two months!

In the matter of only 2 hours…

Andy Callaghan — Tue, 12 Feb 2008 23:08:08 +0000

I have been looking frantically for ‘internships’ for my next University year. I spend a year in the computing industry working for a real company on a real project, earning real money and hopefully setting me up for my career after I leave Uni.

I originally applied to (a very large non-Microsoft company) – as you do. Being my super-duper numero-uno choice for a placement, I applied for their Software Engineer intern in London on their first day that they started accepting applications – 1stÂ November ‘07. Look at me trying to be organised!Â

After a good month of no response from them, I was forced to begin looking elsewhere for placements.

I picked a local company to Reading that specialise in financialÂ institutionÂ web design (banks basically) which I’d prefer not to name in case i get sued for libel or something. When they gave a set of guest lectures, they appeared to be a young but relatively experienced web company which was uber-local to the University – perfect!

After applying to their intern scheme, and a few emails between me and a big cog in the company, I’d secured an initial interview.Â After this first interview I believed I performedÂ reasonably,Â and when they offered a second ‘more formal’ interview, I thought it could only mean good things.

The second interview then passed, and they told me that they would get back to me with a decision by the end of the month (January).Â

29… 30… and the 31st of Jan passed and noÂ response – I feared the worst.Â

These fears were confirmed in the worst possible way by me discovering that one of my course
acquaintances showed me his acceptance email from them. Not the best way to find out you don’t have a job…

Shortly after I got feedback from the internship officer at Reading. She said that the company could not fault my interview, but only said I ‘had asked for too much money during the interview’. Bullplop! They asked me what the average internship wage was, in which I responded with Â£14k minimum (which isÂ coincidentallyÂ what the Big M offer…), and the offer that came through as acceptance was for Â£13k. Rudeness!

Anyway, I digress… After this setback, I was forced yet again to rethink my options, and after a meeting with my internship officer, she secured me an interview with a largeÂ pharmaceuticalÂ company based in the States, but with offices near Reading.

After the painless interview, I believed that I had performed well (but I thought the same before). My placement officer told me that the decision would be relayed to me later in the evening of the interview (last Wed).

At 9pm I checked my inbox, and not only found a ‘Congrats’ email about the previous pharmaceutical company, but also aÂ responseÂ from (a very large non-Microsoft company) !! WOOP WOOP! I saw it and literally leapt into the air in celebration.

The email explained that I wasn’t suitable for the Software Engineer internship, but the Associate Product Manager job was! This intense job allows an intern to direct the shape a handful of their products: released, unreleased, free, or multi-billion dollar a year – It’s all the same!

I am understandablyÂ ecstatic at the prospect of this, and I can’t wait until I have a chance to show off what I canÂ achieveÂ for the company.

Updates will follow, I guarantee.