Wednesday, August 17, 2005


Kijk, da's Sam, "mijn" hond. Ik voel me niet echt prettig bij het idee van eigendom bij levende wezens, vandaar "mijn" tussen aanhalingstekens. Het is net zozeer mijn hond als mijn kinderen mijn eigendom zijn - niet dus.

Sam, 7 weken

En hier zijn 'the brothers in arms', gebroederlijk in 1 mand:

Sam en Sepp
Sepp is van mijn vrouw, en is inmiddels drie. Hij heet Sepp, omdat hij eigenlijk een duitse staande draadhaar zou worden; naar Sepp in het boek van Rien Poortvliet. Of naar Sepp Maier - wat je wilt. Uiteindelijk is het een Epagneul Français geworden, omdat onze eerste hond, Terry, dat ook was. Een afdankertje, maar wat hebben wij een plezier aan dat beest beleefd! Eigenlijk hebben we daarna nooit zonder hond gezeten, en nu dus twee. Prima honden, afkomstig van de kennel Fleur de Zelande. Wel een eind rijden, maar de moeite waard! Hier is nog een andere site, waar de fokster Jessica zelf op te zien is.
Vooruit, hier is er nog een, uit Februari 2005:

Sam, 6 maanden. En voor de volledigheid, Sepp in zijn jonge jaren:

Sepp, 10 weken

Sunday, August 14, 2005

Magnetic RAM (MRAM) and Spintronics

The latest RAM (Random Access Memory) chips are based on the spinning of electrons, not on the mere presence of electrons.

Many of you know, electrons are negative particles, circling around a positively charged atomic nucleus. Modern physists have problems with that image, as the electron is not just a particle, it's also a wave. And, on top of that, not only does an electron circle around a nucleus, it also spins, circles around itself.
It either spins clockwise, or anti-clockwise (you could also say: it always spins in the same direction, but some electrons stand on their head). This could just as well represent a binary '0' or '1' as (electrical) tension, or current. And that is what MRAM is all about.

As you were told in highschool, electric current and magnetic fields always go hand-in-hand. Move a magnetic field, and you will get an electric current; an electric current will generate a magnetic field.
Transformers are built on this principle: you send (alternating) current through a wire, thus generating an alternating magnetic field. You place a coil in that magnetic field, and a current will result from that. As the magnetic field itself "moves" (it alternates), your coil will keep picking it up. Another rule was the corkscrew rule, defining the relation between force, direction of current and magnetic field direction.

Now, remember those pickup coils on the magnetic drums called computer storage? Those coils actually had to pick up the magnetic field, causing a minute change in electric current (one percent would be normal). Higher density disks, with higher throughput, call for those magnetic fields to become smaller, but also for pick up mechanisms to become smaller. All this causes more 'noise', thus making it extra hard to distinguish the noise from the signal.
Until... Giant Magnetoresistance (GMR) was discovered by Albert Fert and Peter Grünberg, back in 1988. This phenomena, best compared to an optical filter like Polaroid glass, causes a change in magnetic fields to be amplified so that the signal-to-noise ratio improves tenfold. Changes in currents would be 10 percent or more (as opposed to one).

A pickup head would be made out of two parts: a fixed magnetic component combined with a variable magnetic component, glued together with a conductive layer. The variable magnetic component would alter with the passing of a magnetic field (from the platter), and just like light with the rotating of two Polaroid glass sheets, current can either pass easily, or not at all. Well, harder, as due to miniaturization, there is a lot of leaking, but as said, ten percent change in current would be doable.
Disk manufacturers, like IBM, have been using the spinning of electrons on disk platters since some time now (there's a beautiful animated explanation on the IBM website), and the size of the magnetic structures has gone back to some 30 by 200 nm (1 nm = 10^-9 m), some 30 nm apart. All this races underneath a pickup head that flies a couple of nanometers above the platters, which has to be able to distinguish billions of magnetic field changes every second.

The next step.

Some years later, magnetic tunneling was discovered. The first thesis was published in 1995 by Jagadeesh Moodera, and the main difference between the pickup element above, which comprised of three (electrically) conductors, the two magnetic layers are no longer separated by a conductive layer, but by an insulator.
Making this layer thin enough (we're talking atoms here; three to five atoms thickness), electrons can tunnel their way through. Now, we're on quantummechanics territory here, not my forte, but the mechanism is much like the electrical tunneling as used in diodes, e.g. I'll leave it with that. And with the remark, that this tunneling effect makes the difference between passing of electrons increase to 50 or 60%.

Last fall, the first prototype of an MRAM memory chip was presented by Motorola and Cypress Semiconductor. According to some, it's not just a prototype, but a working product, available to companies that want to incorporate it in their products. It's capacity (256 kilobit) is not large enough for any serious use (even your phone uses several Megabit!), but it's a serious start.

By now companies like IBM, Motorola and not since long, Intel, are planning commercial introduction of MRAM, so not much details are revealed. It must be clear, that all has to become smaller, and faster. If all that comes true, picture this:
cellular phones and MP3 players which need recharging only when used. PC's starting up in seconds or less, because the Operating System is loaded off MRAM.
Watch your local store this autumn.

Want to keep up-to-date? Take a look here

Saturday, August 06, 2005

Holiday Season

It's been a while since I posted here. Partly because I've been busy, partly because it's the holiday season, and I value outdoor life over sitting behind a desk when the weather is nice. Enjoying the barb (just purchased a new, larger model), dogs, whine, sun, etc. Which reminds me...

Things I still want to write about:
  • BPEL. IDC wrote a favorable report on BPEL and the use my employer made in local governmental solutions, unfortunately not a public report, but you can have it for $4,000 US. Or contact me, of course.
    The solution even brought us the Oracle 2005 Innovation Award. As I have been involved in the architecture, and was also involved in Web+ (before being knocked down and went out-of-business for a year) in the beginning, this is something I'm proud of.
    The Message Bus and Operational Data Store stuff comes right out of a presentation I gave to the Arnhem civil servants on Data Integration (part of the BRIN project), back in early 2003. The idea is a spin off of the VIAG project, back in 2001.

  • The dogs we have, two Epagneul Français. They give my wife and I a lot of comfort and joy. And they're cute in a sort of way a 35 kg dog can be cute. Very ancient race, goes back to the 12th(!) century.

  • RMAN. Started a booklet, an adventure with RMAN some time ago. Should be finished and published.

  • HTMLDB. Been working with HTMLDB for the last couple of weeks, and I'm impressed. If you haven't done so, take a look at it. There's a playground with Oracle itself, so go ahead and request a workspace. The site just updated to V2.0, which cannot be downloaded yet. Haven't seen in V2.0 much to be impressed by, yet.
    No, I wasn't impressed by the graphics/dropdown stuff. It's implementation I find clumsy, with Javascript, where it could have been XML/DHTML. For some good examples, take a look at Stu Nicholls CSS Playground. All the pictures and stuff could be replaced by Snazzy Bordered Menus. Take a big byte out of your traffic - not a page on the project I do now, exceeds 7kB - yes, that's seven KiloByte!

  • Belgium. Forgot to congratulate our Southern neighbours with their 175th anniversary. Nou, awel, alsnog dan bij deze, eh mannekes? Ik vat er nog wel een pintken op! Of twee.

  • Enterprise Security part X - wrap up. Yes, I know... TDE works though.