Learning Computers and Computing

I have been doing research into the nature of computers and I’ve been participating with with the phenomena know as Coderdojo. As part of my research I’ve been relearning Assembly language on several different architectures, and I’ve been experimenting with such things a the ELF Membership Card which I soldered myself and is currently running in front of me, along with a Arduino Uno. These both represent small microprocessor, very like the ones I personally started out on.

My first computer was an Apple II+ with a Motorola 6502 processor. But in any case, this act of relearning what a computer really is has made me aware of the lack of any real education ‘tools’ like I had. The sensation that is the Raspberry-Pi is fast becoming the CPU-du-jour of the developers, and as such may develop into a great educational tool. But, and there is always a but, it doesn’t stand on it’s own.

The group who developed the Pi have themselves noted that this is a developmental prototype, and that it needs to be distilled into a real educational product. It first need a keyboard, mouse, display a SD-Memory card and a power supply, to even turn it on. To make it useful as a net-workable it also needs a connection to hardwired Ethernet. It needs to have software preloaded onto the SD-Memory to boot properly. These are Geek requirements, anyone who can make this work, ALREADY has working knowledge and equipment, call it infrastructure, to make this work. What is missing in this is a standalone environment that is self contained and independent of both other systems, and other foreknowledge of computing.

My Apple II came with a keyboard, memory, built-in BASIC programing language, and displayed it’s output into a common Television, and recorded and loaded programs from a simple cassette player. All these elements were basic, everyday items in my household, and it would plug into the mains power directly, and display on a TV. It started up using Applesoft BASIC language and displayed on the screen everything I typed.

The Rasberry-Pi now needs this type of infrastructure. And while on this subject, and not to stir a pot, comes a language issue. The apple I learned on came with BASIC and in fact I still have a fondness for BASIC. The current arguments in the ‘Programming Education’ discussions are that a language like BASIC teaches BAD programming practice. Be in old, I had to remember the motivations of BASIC and was more enlightened to connect this with my reeducation about Assembly language. That was the first reason for BASIC! BASIC is and was engineered to, more or less, follow the structure of the instruction set of the CPU itself. Where language snobs see bad ‘GOTO’s in BASIC, I see machine language Conditional and unconditional ‘Branch’ instructions. Where I see a BASIC with line numbers (not all BASICs have them) I see ‘Linear’ machine instructions.

One element of the Raspberry-Pi that also misses the mark, is the nature of ‘abstraction’ while I admire the Python of the Pi, and the ‘C’ like language of the Arduino, what is missing is the distance between the learner programmer and the actual machine. It may even be a serious problem as the machine begins to look like magic, and that it can be made to do anything.

The programming of the RCA 1802 chip contained in the ELF Membership Card demonstrated what the creator of the card referred to as ‘Bare metal programing’. A simple program that I used to test the ELF with consisted of 12, 8 Bit instructions, writing (essentially) the same program for the Arduino required downloading of 998 8 Bit instructions (not including the 512 Bytes of the boot loader). To be sure there were probably a lot of libraries included in that download. Helpful, but masking the actual operations of the CPU from any real educational product. Just like that Arduino, the Raspberry-Pi will mask the CPU, and the associated hardware by a boot loader (BIOS), followed by a full, though striped to minimum, Linux kernel, and a GUI in the form of LXDE X-Windows, followed by Python language. That’s a lot of abstraction!

All these things may be irrelevant in the long term, one thing may lead to stimulation to explore the ‘Bare Metal’ hardware of the Raspberry-Pi while allowing a positive feedback with easy ‘wins’ on top of the abstraction provided. Still I believe we are missing an opportunity to produce the next generation of computer wizards. I also believe that someone needs to integrate the Rasberry-Pi into a OLPC type of device.

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3 thoughts on “Learning Computers and Computing

  1. Hi Randy,
    Some really great thoughts above. I’m hoping RPi+Arduino will make kids eager to get closer to the metal.

    However, regarding your concerns about the initial user experience on the RPi, I think you have made the same mistake I did. The current release is a developer preview. There was never any intention to put it in the hands of kids at this stage. The plan is to have a great out-of-the-box experience with a far better UI etc when they go for full release.

    Given that they still have major USB issues (and ever-reducing SD card issues), this approach has turned out to be a good one.

    My only worry is that the hype curve will fade before they are properly production-ready. But then Clive Sinclair used to always announce his products months before they were ready and that turned out ok :-)

  2. Thanks for the comment, but I do understand that the Pi is still developer grade, the location of the connectors makes it way too fiddly to be of general use. I am looking forward to it’s arrival, and I have visualized a perfect kit/configuration to exploit it’s abilities. Want to go into business with me?

  3. I’ve had a few thoughts around kits but all are far beyond my limited craft skills. I particularly like this Adafruit case but shipping to Ireland is crippling.

    https://www.adafruit.com/products/859

    The one I’m making at the minute is based on an overly-large Maplin box. But I’ll have to wait for my first ever Dremel to arrive so I can cut the holes properly.

    Both of will have to grow beards, drink warm beer and go to Cambridge :-)

    http://en.wikipedia.org/wiki/Micro_Men

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