Cable management

I recently found a nifty solution for the crippling problem of cable management. It might not be suitable for super computers but it does work for my desk.

It was built by screwing Ikea Antonius coat hangers to the underside of the desk using long enough wood screws. To give it a bit of stability, I used a hollow tube (like piping cut to length) for the hangers to sit on.

Here are a few pictures:

Simple and inexpensive…

Due to popular demand, here is a diagram I cooked up in paint that better explains the mounting mechanism. I have no particular suggestion for the length of the pipe except that it should be long enough for the hanger to clear the table (so you can slide the cables in). If my memory is correct, mine are 8cm. As for the screw, just make sure it is long enough so it can drive a good 2cm in the table.

Sorry for the lack of information, next time, I will be more thorough in my description and will take more pictures.

Modern screen savers are useless

I once owned a monitor with a permanently printed windows 3.1 desktop on it. It was still usable, but when turned off, you could see the damage well enough to read the windows menus on the normally dark screen. This monitor was a 13 inch black and white CRT that was probably manufactured at the very beginning of the 1990s.

CRT are just electron guns aiming at a phosphorous surface. When an electron hits that surface, an electron belonging to a phosphor atom gets excited and when it drops back to its normal energy level, it emits a photon of a certain frequency. Repeat the same process many times per second and in an ordered fashion and you will be able to display graphics. When the image on a CRT is left standing still for a long duration, the repetitive hit of electrons on the inside phosphorous layer degrade it, making it more transparent where the image is the most bright. Screen savers were invented to prevent this phenomenon; to save screens that were left on.

With LCDs, there is no such phenomenon; using a screen saver is dumb and only wastes power. Instead, set your computer to put it in standby after a few minutes of inactivity, or discipline youself and turn it off using the power button, which is better because the screen uses less standby power that way.

Netbooks: the return of terminals

Rings a bell? They are not so common nowadays and are often associated with vintage technology, except in libraries, where they very often serve the sole purpose of consulting the database. But a while ago, terminals were pretty much the only alternative to fiddling with punchcards on a mainframe. Back then, it was not possible to build a personal computer that had enough resources to do anything other than add a bunch of numbers together, or at least at a decent price and size. Displaying a text document is a very tricky task when all you have is 256 bytes of ram…

Terminals died as silicon shrunk and became more affordable; so much that by the 1980s, they had pretty much vanished as a sensible option. At the beginning of the 1990s, they made a limited come back as X-terminals, or simple computers that only run a X server and rely on a bigger UNIX machine to take care of the actual work. It was rather ephemeral, although most Linux users still get to enjoy the venerable as their windowing system.

A few days ago, I came across a quite interesting article by wired. To make a long story short, it explains how netbook sales will very soon pass notebook sales, mostly because of their relatively lower price tag, that they make perfect internet workstation, and that third world citizens can almost afford them. It does make a lot of sense if you look at what people use their computers for: Facebook, surfing, Facebook, e-mails you get from Facebook, Facebook, chat with Facebook, music, Facebook, movies, Facebook, pr0n, Facebook and the occasional word processing. Basically, they rely on the internet for most of what they do and the programs they use, beside a browser, tend to be very lightweight. The story becomes different if you add games to the equation (although nowadays, most use consoles), but in short you don’t need a 2999$ alienware 20 inch, Quad Core, SLI, RAID 0 laptop that you keep on a table anyway because its too big and heavy and overheats, to do that (Facebooking). I suppose that segment of the portable computer market will gradually shift towards being niche as the trend reverses itself, where pure power used to push sales, it is now size and affordability, so much that the crowds who used to thrive on multigigahertz monsters, now find the concept of netbooks quite convenient for day-to-day computing.

It totally makes sense from an economical perspective for people to buy netbooks, but what about terminals? Well, if you think about what I previously said, it seems netbooks fit perfectly the case of terminals, where the web is the mainframe, and your browser a window to it. There is very little you cannot do online, google docs, Facebook, chat, music, movies, everything is there, even image processing, the rest of the activities concern only 5% of all users. You said games? Well, AMD has a rendering farm in the works. Imagine playing World of Warcraft on the bus, wow! The wired article does bring up that point; that things are shifting. Shifting back to what they used to be: terminals. But this time, different terminals, and at-times, terminal will probably be used as a relationship rather than a moniker to describe hardware, like client-server. Kevin Kelly entertained the TED crowd with a very insightful talk, about the next 5000 days of the web, that was all about the concept of that new kind of terminal. To describe the relationship between personal computers and the web, he stated that personal computers would only be windows to the “One”, or terminals looking inside the immense machine that is the web. However, as parts of the web, they would also be looked into by other terminals, thus making “terminal” a relationship.

While I will not dig further into futurology, the perspective of that one big web really excites me. But what I am wondering, is if that terminal versus standalone time function is not periodic. If software will not become once again so demanding, that it will no longer be possible to distribute it until the network catches up. As with all things, time will tell.


An instanton or pseudoparticle is a notion appearing in theoretical and mathematical physics. Mathematically, a Yang-Mills instanton is a self-dual or anti-self-dual connection in a principal bundle over a four-dimensional Riemannian manifold that plays the role of physical space-time in nonabelian gauge theory. Instantons are topologically nontrivial solutions of Yang-Mills equations that absolutely minimize the energy functional within their topological type. First such solutions were discovered in the case of four-dimensional euclidean space compactified to the four-dimensional sphere, and turned out to be localized in space-time, prompting the names pseudoparticle and instanton.

Source: The wise wikipedia

RIP HP Deskjet 4L

My old laser printer, an HP DeskJet 4L (1994 – 2009) recently passed away. It wasn’t a quiet and peaceful death though. Most of electronics will die without you noticing until you actually try to use it but for that printer it suffered a horrible end during surgery when I broke a critical connector. I then pulled the plug and pronounced it dead. It will be buried in my e-waste recycling bin and there will be a service for friends and family to attend.

A few days ago, while printing some documentation and code, the stepper motor started gripping and after a few more pages, the printer completely stalled. Judging by the sound of it, it was a mechanical blockage that was causing enough resistance to prevent the motor shaft from rotating. I then spent a fair 6 hours looking for the problem until I found it was the pressure and developing rollers that were rubbing too hard against each other. As usual, it took way too much time to figure that out; I did inspect this part of the printer in the beginning but there was little sign of wear and nothing actually stuck in there. Upon visual inspection, I could not find what was wrong with it and what caused the sudden failure, so I decided to rebuild it. Then, while inspecting and cleaning those rollers, I accidently broke a contact pad of the heating element inside the developing roller, thereby rendering the printer useless. I could go and look for a replacement part, but it is not worth my time as the age of the machine will most likely make the search long and tedious, I mean, who owns a 15 year old printer nowadays?

On the bright side, I got to completely take apart a fine piece of machinery, something I had not done for a while (And something all makers have in common: the love of disassembling stuff and voiding warranties). This printer was like a Russian T-35, slow, ugly and simple, but very reliable and sturdy. The mechanisms are very rugged and simple; the electronics are of good quality and so are the metals but above all, the plastics out of which the frame and cover are constructed are of exceptional durability. This printer did get a few kicks and had to handle a few more Gs that what is prescribed for safe operation. The service manual was also exemplary, more than 300 pages long, it listed and explained the functioning of every component down to the screw and even provided the reader with comprehensive block diagrams of every sub-system. When you compare this printer with today’s flashy ones, you quickly realize that the need to drive costs down has made them cheap and short-lasting; the difference is readily noticeable, even for the untrained eye. In fact, they have become so inexpensive that they are considered by some as consumables. Back when I used to work at a small computer store, we used to sell Epson printers for cheaper than the cost of new cartridges and some customers who repeatedly bought them told me that they found it more economical to throw the printer away and buy a new one while the deal was on. Thinking about it, this was catastrophic and it is the very cause of why we are now buried in so much e-waste: the consumption paradigm.

On that line, Platform 21 suggested a repair manifesto that I find quite pertinent and try to apply for most of my possessions.

I still have an old HP DeskJet 5L at my parent’s place, it has paper feeding problems, but it should be an easy fix. In the meantime, go find something that is defective and give it a new life!