Paul Boddie's Free Software-related blog

Archive for January, 2013

Why the Raspberry Pi isn’t the new BBC Micro (and perhaps shouldn’t be, either)

Wednesday, January 23rd, 2013

Having read a commentary on “rivals” to the increasingly well-known Raspberry Pi, and having previously read a commentary that criticised the product and the project for not upholding the claimed ideals of encouraging top-to-bottom experimentation in computing and recreating the environment of studying systems at every level from the hardware through the operating system to the applications, I find myself scrutinising both the advocacy as well as the criticism of the project to see how well it measures up to those ideals and whether the project objectives and how the way they are to be achieved can be seen as still being appropriate thirty years on from the introduction of microcomputers to the masses.

The latter, critical commentary is provocatively titled “Why Raspberry Pi Is Unsuitable for Education” because the Raspberry Pi product, or at least the hardware being sold, is supposedly aimed at education just as the BBC Microcomputer was in the early 1980s. A significant objective of the Computer Literacy Project in that era was to introduce microcomputers in the educational system (at many levels, not just in primary and secondary schools, although that is clearly by far the largest area in the educational sector) and to encourage learning using educational software tools as well as learning about computing itself. Indeed, the “folklore” around the Raspberry Pi is meant to evoke fond memories of that era, with Model A and B variants of the device, and with various well-known personalities being involved in the initiative in one way or another.

Now, if I were to criticise the Raspberry Pi initiative and to tread on toes in doing so, I would rather state something more specific than “education” because I don’t think that making low-cost hardware to education is a bad thing at all, even if it does leave various things to be desired with regard to the openness of the hardware. The former commentary mentioned above makes the point that cheap computers means fewer angry people when or if they get broken, and this is hard to disagree with, although I would caution people into thinking that it means we can treat these devices as disposable items to be treated carelessly. In fact, I would be as specific as to state that the Raspberry Pi is not the equivalent of the BBC Micro.

In the debate about openness, one focus is on the hardware and whether the users can understand and experiment with it. The BBC Micro used a number of commodity components, many of which are still available in some form today, with only perhaps one or two proprietary integrated circuits in the form of uncommitted logic arrays (ULAs), and the circuit diagram was published in various manuals. (My own experience with such matters is actually related to the Acorn Electron which is derived from the BBC Micro and which uses fewer components by merging the tasks of some of those omitted components into a more complicated ULA which also sacrifices some functionality.) In principle, apart from the ULAs for which only block diagrams and pin-outs were published, it was possible to understand the functioning of the hardware and thus make your own peripheral hardware without signing non-disclosure agreements (NDAs) or being best friends with the manufacturer.

Meanwhile, although things are known about the components used by the Raspberry Pi, most obviously the controversial choice of system-on-a-chip (SoC) solution, the information available to make your own is not readily available. Would it be possible to make a BBC Micro from the published information? In fact, there was a version of the BBC Micro made and sold under licence in India where the intention was to source only the ULAs from Acorn (the manufacturer of the BBC Micro) and to make everything else in India. Would it be desirable to replicate the Raspberry Pi exactly? For a number of reasons it would neither be necessary nor would it be desirable to focus so narrowly on one specific device, and I will return to this shortly.

But first, on the most controversial aspect of the Raspberry Pi, it has been criticised by a number of people for using a SoC that incorporates the CPU core alongside proprietary functionality including the display/graphics hardware. Indeed, the system can only boot through the use of proprietary firmware that runs on a not-publicly-documented processing core for which the source code may never be made available. This does raise concern about the sustainability of the device in terms of continued support from the manufacturer of the SoC – it is doubtful that Broadcom will stick with the component in question for very long given the competitive pressures in the market for such hardware – as well as the more general issues of transparency (what does that firmware really do?) and maintainability (can I fix bad hardware behaviour myself?). Many people play down these latter issues, but it is clear that many people also experience problems with proprietary graphics hardware, with its sudden unexplainable crashes, and proprietary BIOS firmware, with its weird behaviour (why does my BIOS sometimes not boot the machine and just sit there with a stupid Intel machine version message?) and lack of functionality.

One can always argue that the operating system on the BBC Micro was proprietary and the source code never officially published – books did apparently appear in print with disassembled code listings, clearly testing then-imprecisely-defined boundaries of copyright – and that the Raspberry Pi can run GNU/Linux (and the proprietary operating system, RISC OS, that is perhaps best left as a historical relic), and if anything I would argue that the exposure that Free Software gets from the Raspberry Pi is one of the initiative’s most welcome outcomes. Back in the microcomputer era, proprietary things were often regarded as being good things in the misguided sense that since they are only offered by one company to customers of that company, they would presumably offer exclusive features that not only act as selling points for that company’s products but also give customers some kind of “edge” over people buying the products of the competitors, if this mattered to you, of course, which is arguably most celebrated in recollections of playground/schoolyard arguments over who had the best computer.

The Computer Literacy Project, even though it did offer funding to buy hardware from many vendors, sadly favoured one vendor in particular. This might seem odd as a product of a government and an ideology that in most aspects of public life in the United Kingdom emphasised and enforced competition, even in areas where competition between private companies was a poor solution for a problem best solved by state governance, and so de-facto standards as opposed to genuine standards ruled the education sector (just as de-facto standards set by corporations, facilitated by dubious business practices, ruled other sectors from that era onwards). Thus, a substantial investment was made in equipment and knowledge tied to one vendor, and it would be that vendor the customers would need to return to if they wanted more of the same, either to continue providing education on the range of supported topics or related ones, or to leverage the knowledge gained for other purposes.

The first commentary mentioned above uses the term “the new Raspberry Pi” as if the choice is between holding firm to a specific device with its expanding but specific ecosystem of products and other offerings or discarding it and choosing something that offers more “bang for the buck”. Admittedly, the commentary also notes that there are other choices for other purposes. But just as the BBC Micro enjoyed a proliferation of peripheral hardware, software commissioned for the platform as well as software written as the market expanded, and even though this does mean that people will be able to do things that they never considered doing before, particularly with hardware and electronics, there is a huge risk that all of this will be done in a way that emphasises a specific device – a specific solution involving specific investments – that serves to fragment the educational community and reproduce the confusion and frustration of the microcomputer era where a program or device required a specific machine to work.

Although it appeals to people’s nostalgia, the educational materials that should be (and presumably are) the real deliverable of the Raspberry Pi initiative should not seek to recreate the Tower of Babel feeling brought about by opening a 1980s book like Computer Spacegames and having to make repeated corrections to programs so that they may have a chance of running on a particular system (even though this may in itself have inspired a curiosity in myself for the diversity seen in systems and both machine and natural languages). Nothing should be “the old Raspberry Pi” or “the new Raspberry Pi” or “the even newer Raspberry Pi” because dividing things up like this will mean that people will end up using the wrong instructions for the wrong thing and being frustrated and giving up. Just looking at the chaos in the periphery around the Arduino is surely enough of a warning.

In short, we should encourage diversity in the devices and solutions offered for people to learn about computing, and we should seek to support genuine standards and genuine openness so that everyone can learn from each other, work with each other’s kit, and work together on materials that support them all as easily and as well as possible. Otherwise, we will have learned nothing from the past and will repeat the major mistakes of the 1980s. That is why the Raspberry Pi should not be the new BBC Micro.