Category Archives: Computers

Learn machine code and C at university for free and at home – Enrol in a MOOC

I usually try and post once a week, but I missed last week because I enrolled in a Computing MOOC and it has been keeping me very busy. What’s a MOOC? It’s a Massive Online Open Course. These are (usually?) run by Universities and they are becoming quite popular. They are offered for free and anyone can enroll. The catch is that at the end of the course you don’t get a certificate of completion and it is unlikely you will be able to do a whole degree.

So why do universities offer these? There are a couple of reasons. One is that it is a way for universities to distribute knowledge across the whole community and the other is that it introduces prospective students to the university.

These are good for the community too. They provide a way to try out university without going through the process of enrolling and paying fees. Just like a normal course you will (or at least in the ones I have seen) be able to interact with your fellow classmates and enjoy the benefits of having a qualified lecturer answer questions. Of course, being online means you never have to leave home to participate. Great for a child that is nearing the end of High School and contemplating university.

The course I have enrolled in is Computing 1: The art of computing, run by Richard Buckland at the University of New South Wales here in Australia. It was created from the UNSW first year computing course. It runs for twelve weeks and covers machine code and C. Lectures are provided through video. These are embedded in the course but they are also available on YouTube. This is the first one.

There are a lot of tasks, but most are short requiring 15 minutes to 1 hour to complete and they are be submitted online. Results are often instant through an automatic marking process. I’m surprised at how enjoyable it is and how enthusiastic other students are. Also, I am surprised by how much I have learnt in just a few weeks.

According to their website the next cohort will be starting on 3rd December 2012. Enrolling is easy – it will only take a couple of minutes. You can even log in with your Facebook account. If you enroll and find it is not for you, you can simple withdraw as there is no penalty. If you’re interested, but computing is not your thing then do a Google search for mooc and the subject you are interested in. It’s likely that you will find something.

Raspberry Pi: I managed to get one of these new cheap computers

Last week I bought one of those new Raspberry Pi computers. It is a small single-board computer about the size of a deck of playing cards. It was developed in the UK by the Raspberry Pi Foundation with the intention of making a cheap computer to be used in schools for teaching about computers as opposed to teaching about Word, Excel and other applications.

A view of the Raspberry Pi computer from above

The Raspberry Pi

There are two main versions. The one I got (and I think the most popular) is the slightly more expensive Model-B which I bought in Australia for about $38.00 (without SD card). While it doesn’t look like it could do much it has a 700MHz ARM processor with 512MB inbuilt RAM (like those used in some mobile phones), 2 x USB ports, composite video output, HDMI output, a 3.5mm audio output, a SD card slot, an Ethernet socket and a micro USB socket used to connect a 5v power supply. It can run Linux (I have a version designed for it called Raspbian) which is installed on a SD card. All that’s needed to start off is a keyboard, mouse and screen (a TV will do) and a connection to the internet (I use a USB wireless network card). The other thing it has of interest is a GPIO (General Purpose Input Output) header that lets you connect sensors and other things.

The Raspberry Pi with retail box and separate SD card

Here it is with the retail packaging. The SD card was purchased separately.

The first thing that stood out is the box. It looks like a box of tablets. I opened it up and removed the small circuit board and spent the next 15 minutes admiring it and passing on all the “interesting” facts I knew about it to my wife until I thought she could take no more. The next day when I had more time I inserted the SD card, connected my phone charger as a power supply, a keyboard and wireless mouse and the TV via a HDMI cable and switched it on. Lots of text came up on the screen followed by a prompt for a username and then password. I read the instructions that came with the SD card that I bought on ebay and got the Linux GUI desktop running. I felt like I did when I got my first Commodore 64 computer. I was excited that I could get it to boot and realised that there was so much to learn. Eventually I got an old USB wireless networking stick to connect to our network so I can put that LAN cable away again.

A view of the bottom of the Raspberry with the SD card in its socket

Here’s a shot of the bottom with the SD card inserted

The thing that is perhaps the most exciting other than the value for money it offers is the potential it holds for hobbyists. Already there is a community sharing tips and project ideas. They are cheap… cheap enough that money is not really a reason to avoid using them. Cheap enough that it doesn’t matter if you destroy one and cheap enough that you can buy a few if you want to have several projects going.

So what are my plans? I’m finding the learning curve is a bit steep at the moment and I’m not very confident that I can get very far with it. Initially I want to get it to run as a server and be able to log into it remotely. Next I would like to see if I could connect a sensor or two – maybe a seismic sensor and be able to monitor that remotely. After that I would like data from the sensor to be stored and remotely accessible.

Computers: The 1990’s – You paid how much?

Black and White laser printer. A bargain in 1994 at $1000

Recently I found a couple of old catalogues in our filing cabinet that I had kept for some unknown reason. I was looking at the prices of computers and was reminded what an expensive hobby it used to be. The catalogue was from July 1996. There were 14 desktop computers ranging from A$2999 to A$4099 with an average price of a whopping A$3412. The $4099 one was described as “Unprecedented power & storage for small business and accounting needs”. Its specs were:

  • 100MHz Processor
  • 1.2Gb HD
  • 12Mb RAM
  • 4X CD ROM
  • 15” Monitor
  • MYOB software

It’s hard to believe that was enough power for a business, but I remember using something similar at the time where I worked and it seemed fine for what we did.

There is also seven laptops listed ranging from A$2999 to A$4699 with an average price of A$3541. For $4699 you could have:

  • 75MHz Pentium processor
  • 8Mb RAM
  • 9.5” Active Matrix TFT display
  • Removable 810Mb HD
  • Lithium-Ion battery,
  • BitBLT Video Accelerator
  • Windows 95

I don’t think that these prices were particularly high for that time, not around here anyway. At that time the Australian dollar was valued much lower than the US dollar which accounts for some of the price difference we now have. According to the RBA Inflation calculator that calculates increases of “baskets of goods and services”, that average price of $3541 back in 2006 would now (or at least in 2011) be an incredible $5,274

Examples of my excessive spending

Here are some of the things that I purchased around that time:

  • Microsoft Office, purchased in July 94. This was version 4.3 and came out for windows 3.1? Fortunately it also worked with Windows 95. I got a discount because it was an upgrade from Works. Price: A$525
  • Diamond CD reader and software kit. Purchased in March 95, this kit had a 4x CD reader (not writer) and a few games and other software including Compton’s Encyclopaedia. Price: A$799
  • 8Mb RAM, yes that’s correct 8Mb, not 8Gb. August 94. Price: A$620
  • B&W desktop Laser Printer. July 94. Price A$1000. It was ok, but not as good as my current laser printer which were selling recently for $49.

Other than making me feel sick at the thought of having wasted so much money, I can at least take comfort that computing is more affordable now.

Redundant faster?

Back in those days second hand items were expensive too. I don’t know if it is my imagination, but there seemed to be a bigger performance difference between new computers then and those 12 months older, and not just for intensive software like games, but even for basic things such as word processing. Because people paid so much for new equipment many expected to sell them for a high price a year or two later, often asking as much as an equivalent new one with the same specs.

I bought a second hand tower in 1994 that had 386SX CPU, 4Mb RAM, 80Mb hard drive, 14” Monitor for $1500. That price was typical around here. Now I would have to pay our local recycling centre to accept it. It did come with a large solid case which had lots of room for expansion, but I never made use of it as extra bits cost so much. It had flip out feet on the bottom that I had to remove just to make it fit under my desk.

386SX PC. $1500 in 1994

386SX PC. $1500 in 1994

It’s not just that hardware is cheaper. A lot of software is cheaper or free too. I remember being quite excited when I purchased Cinemania on CD. Now IMDb  contains everything and more that I want to know about movies and is available online. The quality of software that I paid $70 or $80 was no better than those that are available online for free now.

We now pay for the internet

I do now have an ongoing internet access cost that I did not have. I have been paying more each year for that, but that’s because I now have a family of four that all love to use it. I still feel I’m much better off now, but it’s worth considering this cost.

It’s good though, isn’t it?

When I think of the cost of my iPad, I remember I paid less for it than the floppy drive for my Commodore 64, which was over $1000 if you take inflation into account. When someone displays a look of horror when I hear someone mention they have actually paid a few dollars for an App, I remember what it used to be like. I guess it’s still easy enough to spend lots of money on computers, but it no longer needs to be that way. I can’t help thinking how much better it is now.