Pi in the sky

[Joe]

Thanks for the reply, Mark.

What I meant was that going on the reports in the general media it would be easy to think you were getting a complete usable system for £30.

As an educational tool or some sort of 'super-PIC' it may well be fantastic.

I don't know what a P2 is so can't comment much further on that. I wouldn't run Windows 7 on anything through choice though.

As for cost of second-hand machines all mine are land-fill refugees so cost even less.

Cheers

- Joe

[Mark Hennessy]

Hi Joe,

Yes, the press coverage has been perhaps misleading, but we all know that journos are prone to over-simplification - especially where tech is concerned. To be fair, the BBC's coverage - well, the bits I've seen - has been pretty good. But having played with one, I must admit that it's more "real" and usable than I expected, although a 10 year old P4 running XP will obviously be of more use to most people wanting a straightforward desktop machine.

A P2 is the second-generation Pentium, which came out in 1997. They were in the "Slot 1" package, which seemed very exciting at the time. Clock speeds varied from 233MHz to 450MHz, which seemed unbelievable back then. I remember stepping from a 200MHz P1 to a 333MHz P2, and the difference was staggering - of course, everything else in the system was correspondingly faster; it's not just the CPU speed. I still have that 333MHz machine - it's on my desk at work, and it gets regularly used, believe it or not. It runs Win98, and runs it well.

The Pentium III went to just over 1GHz, and I have a few of those around as well. The P4 reached nearly 4GHz, but 3.2GHz is fast as I have - and that consumes nearly 100W when it's working hard... The faster P4s are still a reasonably viable machine for everyday use today for most people, but they are very power-hungry (and therefore often noisy) compared to more modern multi-core processors. The advantage of most P4 motherboards is that you can normally use up to 2GB of RAM, which is key to running XP well. Most P3 motherboards I've seen are limited to 1GB, and the DIMMs needed for these tend to be more expensive.

Grudgingly, Windows 7 is actually very good indeed. I didn't want to like it, especially after suffering Vista previously, but they've got things pretty right with 7 - in my experience, providing the hardware is supported, it "just works", though no-doubt the anti-M$ brigade wouldn't want to agree. I don't run it at home because XP is currently fine for what I need, but I use it at work, and am glad that I'm not stuck with XP - it is an old OS now that struggles to run the large and complex applications in our corporate environment. But it's horses for courses, of course. Win98 is fine on my old P2 machine mentioned above, but I only use that machine for very specific tasks that require the direct access to hardware that Win9x offers and NT doesn't.

Joe, I'm with you - last time I bought a new computer was in 2004, and that was in kit form. Apart from new hard drives, I don't spend money on new computer bits. This machine recently had a graphics card upgrade (£20 eBay - the card was >£200 new!) and it got a CPU upgrade from a junk machine with bulging electrolytics. My "server" machine, running Ubuntu, was landfill, but with an eBay CPU and RAM upgrade it's now pretty usable. I have boxes of computer hardware salvaged from skips - all from the P4 and before era - so if there's anything anyone wants, just ask...

Cheers,

Mark

[Joe]

My desk-top system is a 500MHz Celeron so I don't know how that fits into the scheme of things. That runs W98se and is fine for most things but struggles with the internet. I don't know if this is the processor, OS or the actual connection (despite having a USB 2 card in it only connects at 11mbs) but it manages the basics.

I'd be inclined to stick to XP as I've always followed the advise to use the oldest software that does what you want it to. My lap-top is a much more flashy thing with Vista on but it doesn't seem much quicker on simple tasks as the OS and other extras are just wasting the hardware's power. Put it like this: if I wanted to write you a letter, from a cold start I'd be typing "Dear Mark" quicker after pressing the power switch on my old machine than the new one; probably faster still on the old Amstrad.

As you say, horses for courses. I don't play games and have very little to do with video. My old system is basically a word processor cum over-grown i-Pod.

I have got a couple of other system boxes I've thought about doing up - they've both got duff hard disks - but don't really need them. It's always fun playing about though so I'll keep your offer in mind.

Cheers

Joe

[Mark Hennessy]

Hi Joe,

The "Celeron" CPUs were cut-down versions of the main Intel Pentium chips - they were pretty similar in all regards, but had less level 2 cache memory. How much difference this made depends on the applications you run, but in practice, I've never really noticed much (if any) difference between Celerons and Pentiums of the same clock speed. The initial Celerons had no L2 cache memory at all, and that did make them a bit of a dog - but even a little cache goes a long way...

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

In fact, I've remembered that my PII 333 that I refer to so fondly above is actually the Celeron version. It was much, much cheaper at the time. And according to that article, it seems that it was rather too close to the performance of the equivalent PII.

If you have a 500MHz Celeron, then it's probably based on the PII core. Depending on the motherboard you have, there might well be some upgrade options lurking in my stores - take a couple of pictures next time you take the lid off. It might be possible to fit a later PIII to the motherboard...

Windows 98 is not the best platform to use for internet access. It's much better to use an OS based on the Windows NT kernel, such as 2000, XP, Vista, 7, etc - you really need proper multitasking and more security over memory access. Also, a lot of modern web browsers don't support Win98 - I've got FireFox 2 on my Win98 machine, but versions 3 onwards require XP or later. Naturally, you really shouldn't be using Internet Explorer - any version, on any OS.

The speed issue will be partly down to the basic performance of the hardware. Modern websites use a lot of complex stuff in the background - a lot of which needs to be interpreted locally on your machine by the browser. In particular, JavaScript is very heavily used on most sites, especially things like Facebook - even this simple forum has a surprising amount. JavaScript is very powerful and the interpreters need to be complex, yet quick. Some websites are entirely generated on the local machine using JavaScript - though some of this is technology for the sake of it IMHO.

The connection speed is less likely to be the issue, although it does depend on what you mean - if my ADSL connected at that speed I'd be pretty pleased (it's only 6.2mb/s at the moment, although normally it's more like 8mb/s). I remember when 10mb/s used to be the norm for wired networks, although of course 100mb/s and 1gb/s is the norm now - but while your local network speed helps a lot with copying big files between your computers, it's unlikely to be an issue for web browsing, where your ADSL speed and ISP are the likely bottlenecks. As you mention 11mb/s, I'm wondering if this is a wireless network (I'm less familiar with the various WLAN speeds, but I think I've seen 11mb/s when my wireless signal is poor). Needless to say, for desktop machines, it's always best to go wired if you can (I have about 50 decent 3Com PCI network cards if anyone needs one). Often easier said than done, of course - I've got a fairly major project that involves installing some cable ducts in a lathe and plaster wall to act as a "riser" between the cellar, first floor and attic. One day...

It's definitely true that as hardware gets faster, the interfaces don't! The extra horsepower is used to animate the graphical interface or make windows transparent (WTF???) - needless to say, all these effects get switched straight off! Programmes don't open any faster as they are much bigger to load into memory - depressingly, it's cheaper to upgrade the hardware than to write programmes properly. It's actually quite refreshing to go back to Windows 98 or even 3.11 to see how quick things could run on really quite limited systems. I remember being really impressed with RISCOS on the Acorn Archimedes, a machine that was a decade ahead of its time. Which gets us back to the Raspberry Pi, which will be able to run RISCOS one day

All the best,

Mark

[ed731pdh]

We used to call the original ones "De-Celerons" when they first came out, that lack of L2 cache was a right pain.

[Joe]

I think you've hit it with Java being the problem as Facebook is plain unusable. This forum seems fine; I used to get a 'Missing Plug-In' error about the clock but installing Flash Player 9 fixed that. I too use FF2 but sadly Ad Block Plus is no longer compatible with that. I've also played about with Netscape but it didn't seem any better so I stuck to what I know.

When I said 11Mbs I was meaning between the wi-fi adaptor and the router, at least I THINK that's what I mean! The same thing runs at 54Mbs on the lap-top - IEEE801.11b as opposed to g. There are reasons I can't hard-wire it.

I'll send you photos and details of my system a bit later to save boring everybody else but will post anything relevant here. Getting the cover off won't take long as I never put the screws back!

- Joe

[ed731pdh]

I have had 25 odd years playing around with micro's in one form or another, having cut my teeth on the ZX81 before moving up to a Spectrum and the RML380Z. Of the latter, a respectable machine, but prone to frying the graphics card if you got your programming wrong.

I also remember the hype 15 plus years ago when the PICs first came out. I have a PIC programmer sitting here on the shelf, collecting dust, doing nothing along with a bundle of 16C64 chips. Why? PIC was being marketed as the computer processor for the common man in the street where in actuality you needed to understand machine code in order to get the best from it, and that was before you then designed the hardware to go around it. PIC was in actuality user unfriendly for the man in the street, and that is quite probably the primary reason why I didnt exploit the device.

Pi is a better step forward for the common user. It's a fully integrated computer on a board that does not require you to design anything around it to get it to work from the off whilst using a software that is reasonably easy to use. With PIC you had no idea what was happening inside when turned on, with Pi you look at the screen and get instant results, something that makes it instantly appealing to kids. In addition to the computer you have the MagPi magazine (www.themagpi.com) which from the off has been written for the base user. The last couple of episodes have been covering basic interfacing with the GPIO and USB port whilst issue 3 gave several pages of downloadable software including a BBC Model B emulator. There is a rapidly growing support base out there on the internet, a lot of it is being generated between the ages of 4 to 16, which was the reason why the Pi was conceived in the first place, to interest children in computing the was Sinclair, Commodore, BBC, Dragon etc. did thirty years ago. Not a bad thing in my book

Finally price, yes I'd agree, some silly hype from the press but look at it this way. £30 for the P1, add at most another £25 if you needed to buy a power supply, keyboard, mouse and connectors. Say £60 to round up. But then I recall the ZX81 when it first came out was a wopping £99 at 1980 prices and you had to build it yourself and plug into a television to see what you are doing. What's changed in 30 years? Nothing but the price and a more capable machine, even at £30 quid cheaper over those 30 years it is still a cheap way of getting an internet capable user programmable computer that you can interface to whatever you like and learn a lot along the way.

I do wonder how many of those people at JPL and the laboratories over here contributing to various space related projects actually started with a basic computer all those years ago. With the Pi, maybe in 30 years we will know. Interesting times.

[Tedzed1]

I also remember the hype 15 plus years ago when the PICs first came out. I have a PIC programmer sitting here on the shelf, collecting dust, doing nothing along with a bundle of 16C64 chips.

That is a blast from the past, years ago I used to program Pic 16C84 wafer cards to enable me to watch the Viasat channels at 5°E.
intended for the Scandinavian countries, 90% of the programming was in English, with foreign subtitles, easily receivable over here.
at the time I had a 1 meter motorized dish, with a churchill D2mac decoder connected to a pace satellite receiver (cannot remember the model no)
and when the encryption keys changed, It was as simple as calling a premium rate no, sometimes the new keys were even obtained before a change, the card could simply be updated by the Churchill box via the remote, no need for a programmer or computer, good job really, as I did not
own either at the time.

You simply tuned the receiver to the encoded channel, and entered the key into the decoder in hex ie: 8F C6 0F 2C 59 57 B3.
this way I obtained the three TV2 channels, filmnet, and TV1000, which used to show rather risky uncensored films after midnight.

funnily enough, official SKY decoder cards up to issue number seven could also be used, so they must have been PIC based, this also gave you
the option of the Adult channel for free, but had to be updated via a card programmer.

[Mark Hennessy]

Hi Joe,

Things get really confusing with web technologies. Believe it or, JavaScript is completely different to Java! It's really unfortunate that they sound so similar, but they are quite different. JavaScript is a scripting language that web browsers understand, and was originally used to generate pop-ups and basic interactivity on a web-page. Java, on the other hand, is a lot more complex. The idea is that code is produced that can run on any platform - not just desktop computers, but mobile phones, embedded computers, Blue-Ray players... The executable code is the same, but every different platform has to run a "virtual machine", which takes the Java programme and translates it into machine code that the host CPU can understand. In a way, it's an interesting attempt at cross-platform standardisation. Some websites use Java, but these seem to be less common these days because you can do so much more with the basic web tools (HTML and CSS), combined with JavaScript.

Flash is yet another extension. These days it's mostly used for YouTube/iPlayer streaming, but it has been used in the past to build the basics of a web page. Like the Java virtual machine, it's one more bit of software that you have to keep up to date on your machine, and yet another potential security risk. The latest version of HTML has support for video and audio streaming, so hopefully we'll see less need for Flash as time goes by.

I've done a lot with PICs, although I freely admit that there was a hell of a learning curve! I really like them - there is something very "pure" about the language, and you can be a total control freak because you know what every single 1 and 0 is doing at any one point in time. I haven't played with the high end devices - partly because I haven't needed the extra power, partly because programming in C becomes necessary. I'd be happy to talk anyone through the process of getting started - it's one of the things I do in the day job...


Cheers,

Mark

[Joe]

A basic explanation of what they are and what you can do with them would be a good start. From the negligible amount I know they seem to expensive and complicated for the sort of things I do but I'm ready to learn otherwise.

- Joe