Scratch – A Great Way To Teach Children Programming

(Originally posted 2007-03-18.)

Some time ago a colleague pointed Scratch out to me. It’s a programming environment for children.

When I was a kid I kind of learnt programming from the Elsevier Monographs my Dad had on his bookshelf. He (who’s probably going to read this) gave them to me for safekeeping some time ago. So I count HIM as my first bad influence. 🙂 But he did insist on STRUCTURED programming, so maybe he’s a GOOD influence. 🙂 Maybe he’s mellowed enough by now to just wait for me to get structured programming for myself. 🙂

Later on we had a Research Machines 380Z at school so I learned more by hands on. Only BASIC and a little Z80 Machine Code.

Then I got a job for 6 months as a professional programmer – before University.

A large part of my Master’s degree was also Computer Science. So I’m proper. 🙂

I won’t bore you with the rest. Suffice it to say I learned to program with a text editor on each platform – and a lot of trial and error and reading manuals, stealing examples, etc. It was an essentially TEXT experience.

So Immi, who’s 8.75, is starting with visual programming. It’s a great way to start. I think it’s much less intimidating than using a text editor. And Scratch is a lot of fun for kids. It allows you to create animations using graphical “characters”, sounds, loops, timers and tests. It’s very much in the drag and drop mode – with the programmer changing parameters in the (jigsaw-like) pieces. It’s rather colourful as well. There’s a thriving ecosystem – with a web site and lots of user-contributed example programs.

So, finally, I asked Immi what she thought of Scratch.

Immi says “Scratch is a good way to teach children how to program and it also teaches them animations don’t just come out of nowhere. :-)”

So there you have it – from a dad’s perspective and a daughter’s.

Not Just People Twittering – Vehicles As Well

(Originally posted 2007-03-18.)

Here’s an interesting BBC News Article: Vehicle warning system trialled.

So let me see now, when we said the fridge would talk to the microwave – as everything would have an IP address – did we really envisage that they would Twitter? 🙂 Can you imagine “The Bloggings of an uncleaned fridge?” 🙂

And can you imagine what’d happen if my fridge started Twittering and next door’s microwave yakked back? 🙂

Seriously, I do like the “wisdom of crowds” element of cars talking to one another to relay traffic conditions. But I don’t like the idea (rather like programmed selling) that cars could all decide to take the same diversion? Or that one car could try to sucker the others into getting off its road.

So it might not just be humans that get smart enough to do this stuff.

And the reason I pick up on this peer-to-peer non-human stuff is because we’re used to central authority on things like weather, travel, road conditions… At least in 2 out of those 3 cars already pick up this information centrally. It’s a shift when it becomes peer-to-peer. Kinda like the shift from Web 1.0 to Web 2.0.

Twittering and Blogging

(Originally posted 2007-03-17.)

Here’s a useful contribution to the debate about Twitter: From a friend’s blog. There’s much mileage in the comments – which is where the action really hots up. 🙂

Actually her blog is in general a good read – but maybe I’m biased as she’s a friend of mine. She’s a Web 2.0 enthusiast with a great line in photos and original art. (If you want a business justification for reading her blog she’s a manager with IBM’s Rational division.)

DB2 9 Memory Requirements

(Originally posted 2007-03-16.)

Twice the “128GB” question has come up in newsgroups (the latest in DB2-L). This sort of thing freaks people out – so let me tell you what I know of the matter…

I was fortunate to attend the T3 for DB2 9 in February. This question came up in the context of some changes to DDF:

In Version 8 communication between DDF’s DIST address space and the DBM1 address space was via CSA (actually ECSA so above the 16MB line) and the Private Area. This had two major impacts:

  • The CPU cost of moving data between the two address spaces (and I’m told there’s some reformatting, which adds to the cost).
  • In extreme cases – large networks of heavy threads – chewing up of scarce ECSA and the DIST private area. (Thread “anchors” reside in the DIST address space and can become large, especially with the new, larger, communications buffer capability.)

So, in DB2 9, the interface between DDF and DBM1 was radically redesigned: Now the communication is done using a z/0S 64-bit Large Memory Object. This is in Virtual Storage above the 31-bit bar. When the DBM1 address space starts up this Large Memory Object is allocated with a 128GB size. Communications take place between DDF and DBM1 using this area: But we’re not talking about data moves and reformatting anymore. So this should cut the CPU. (And it also removes the constraints I mentioned above.)

There are two key points here:

  • This is Virtual and not necessarily Real memory.
  • The 128GB object is not populated at creation time. So in all case (at least for now) 🙂 the Virtual usage is going to be an order of magnitude or two less than 128GB.

Virtual does drive Real usage, of course. But in this case the increase in Real memory requirement (and there’s bound to be some) is nothing like 128GB.

I should also point out there will be some Virtual storage savings – below the 2GB bar. That will be welcome to a number of customers I know. (And I may well blog about this soon.) But one caution:

I do not expect the need to manage thread numbers and thread footprints to go away, perhaps ever

DB2 9 does not move the whole thread footprint above the bar. And threads still cost Real memory – though it would take many thousands to have an impact on memory capacity planning. You do do memory capacity planning, don’t you?

Famous Names on Twitter – And Is It Going To Change The Face Of Politics?

(Originally posted 2007-03-14.)

On Twitter I once followed Steve Wozniak – but it turned out not to be him. 😦

Now I’m following John Edwards (and it really does appear to be him). See his Twitter page. I say “it does appear to be him” because the twitterings seem to support that conclusion, plus there is a photograph of him (not that that’s strong evidence). (The ones for the supposed Steve Wozniak never gave credence – it was just a name.) I also see someone claiming to be Barack Obama though this time there are no twitterings (and no photograph).

So there are two issues that come out of it:

  • How do you authenticate a voice when it claims to be someone – especially someone famous? And couldn’t someone sign up claiming to be eg Hillary Clinton and then post stuff damaging to her campaign?
  • Is this cheap-to-mount personal campaigning style going to change campaigning?

The precedent for all this is the famous person’s blog. I follow but one of these, BTW: Brian May’s. (And he’s only just conceded that his “soapbox” is indeed a blog.) 🙂 But this is a little different as Twitter is much lighter weight: It’s easy to throw out a one-liner in Twitter. It’s rather harder to do that with a blog: People expect more of you.

3G Card and Sufficient Rurality

(Originally posted 2007-02-24.)

I’m writing this in the back of a taxi – on my way to Heathrow. (A 3G card for my Thinkpad was waiting for me when I got home yesterday.)

My conclusion is that we live somewhere “sufficiently rural” as I’ve lost signal once. (That was between us and Henley.) Any more than that and I’d think we lived in the sticks. As it is to actually lose the signal at all is a reassurance that we don’t live anywhere urban(e). 🙂

And, no, I wouldn’t really mind if this “test drive” utterly failed: I only really need the card in places where the likelihood of a signal is strong anyway – such as airports and on trains.

Wikipedia

(Originally posted 2007-02-18.)

Whatever one’s feelings about the definitiveness of Wikipedia a lot of people find themselves there, looking for information. Having twice anonymously edited articles – in one case to correct an error, in the other to add a minor snippet – I finally succumbed to the urge to get an ID. So my efforts aren’t quite so anonymous – and are therefore a bit more accountable.

I’m not going to go overboard with the literary style. And in any case with wikis the first writer is often not the one to beat it into shape. So you’ll see me contribute to pages on such subjects as z/OS and z9. (I just created the MIDAW page, for example.)

Come and join me! There’s much work to do on the mainframe-related pages.

DB2 9 and End Of Service For DB2 Version 7

(Originally posted 2007-02-08.)

Willie Favero is also blogging about this – and I stole the link from him…

Here’s the End of Service announcement for DB2 Version 7. It goes out of service on June 30, 2008.

I’ve just sat through four days of the T3 class for DB2 9 for z/OS – in Silicon Valley Lab. My “take home” message is that there’s lots of stuff in all the usual areas. It’s a truly exciting release.

Note: It’s “DB2 9” and not “DB2 Version 9” at this point.

So, with the End of Service announcement for Version 7, coupled with what I know of 9, Version 8 is a great place to be right now – in my opinion.

More on DB2 9 later.

z/OS Release 9 is Previewed

(Originally posted 2007-02-08.)

See the z/OS Release 9 preview statement if you’re interested in z/OS.

There are lots of interesting Performance items previewed, as well as other line items.

It’s expected to become available in September 2007, following the current pattern of a new release each year (preview in the so-called Spring :-)and release in the Autumn) so expect lots more information on it later this year.

I do wonder how many customers will find today’s LPAR limit of 32 processors (CPs plus zIIPs plus zAAPs) to be a constraint. z/OS R.9 is expected to support 54 in total (CPs + zIIPs + zAAPs).