Blinking Lights

I’m sure that if you’re more than twenty, you’ve seen one of those really bad Sci-Fi movies with computers with lights everywhere. As the computer worked, computing at incredible speeds of course, the lights would flash like crazy, often accompanied by weird beeps and bops. When the computer completed its computation, like some kind of bizarre oven, the computer would make a loud ding! The answer would then be printed on a teletype with a characteristic loud buzzing noise.

The IBM 370 (from Simon Fraser University Network Services. Click on image to follow original link.)

__MODULE_DEBUG_TOOLS__

Yesterday, at least at the time I am writing this entry, I spoke about the Zune and its time bug that caused so many of the devices to just freeze on boot. It its clear that this bug is the result of poor testing (in addition to a poor implementation of a conversion using loops rather than explicit divisions and moduli) and this week, I’d like to tell you about one of my tricks to debug code.

Throwing in More Hardware?

In a recent blog entry, Jeff Atwood makes the case that “hardware is Cheap, Programmers are Expensive”, basically arguing that in a lot of cases, it’s cost-efficient to add cheap, faster, hardware to a performance problem rather than investing time to actually enhance the code at the algorithmic and implementation level.

I do, however, disagree with him on many points.

Honni soit le Hongrois

The original Hungarian notation is due to Charles Simonyi who invented it sometimes while he was working at Xerox Palo Alto Research Center—the Xerox PARC that gave us the mouse and the first graphical user interfaces. The basic principle of Hungarian naming convention is to prefix the variables with one or many particles, encoding alternatively its type or its intend. This lets programmer write prgszNames as a variable name, which is perfectly legible to one well versed in Hungarian; however, but looks mostly like gibberish to just anyone else.

I recently changed my mind about the Hungarian naming convention. I don’t think it’s that stupid anymore.

The Zunes Freezes: Update!

The faulty code was leaked some time last week, and I’ve looked at it, and, well, it’s surprisingly clean (despite the obvious defect and how they should’ve found it before releasing it (see here)).

Have a look at the ConvertDays routine.

Cleaning LCD screens

I’m sure that, like me, you’ve tried all kinds of chemical cleaners to clean LCDs. But, like me, also, you’ve noticed most of them leave smudges that you can’t get rid of. Window Cleaners are also rather bad at this, and they may be too rough for the coating of your LCD screens.

However, I think I finaly found what it takes: 50% isopropyl alcohol. That’s right, common rubbing alcohol you can get for 3$ at your local drugstore. Even better, they sell it with a spray cap, for your convenience. Just spray alcohol on a clean, soft, non-linting rag (like a paper towel) and clean your screen gently. Do not spray at the screen directly, because it may cause some of it to leak into the electronics and cause much mayhem. It may take a few application to remove all of the previous chemical cleaner’s residues… but I haven’t seen my screens that clean in a long time.

The Zune Freezes: A Stupid, Avoidable Bug.

The few Zune users where alienated today when they discovered that their Zunes just froze during boot. Apparently, a mysterious bug.

The cause of the bug was rapidly diagnosticated. According to Itsnotabigtruck on Zuneboards, the bug can be traced back to a defective date conversion routine. I reproduce here the code for you:

year = ORIGINYEAR; /* = 1980 */

while (days > 365)
 {
  if (IsLeapYear(year))
   {
    if (days > 366)
        {
         days -= 366;
         year += 1;
       }
   }
  else
   {
    days -= 365;
    year += 1;
   }
 }

Can you see what’s just wrong about that code?

About NDAs

Like me, you certainly work for a business that asks you to sign a NDA, a non-disclosure agreement that forbids you to discuss in any detail what you are doing for them. Apparently, not all people seem to understand what a NDA means. Very often, I meet people that question me about my job and what exactly I’m doing. Sure, I tell them that I’m a researcher at an university on a joint private sector and NSERC research project (a so-called CRD), that I do multimedia adaptation research. Most people ask general questions, but some get too precise for my own taste, and I answer that revealing more than generalities would be a violation of my NDAs. Yet, they press me with more questions.

Sometimes I answer the questions, albeit not in a way they expect.

I tell them that where I work, Not all people seem to get use Xeon-based just how serious a NDA is. On a regular basis, I hear friends complaining about events that happened at their Python workplace, often and state-of-the-art quality control involving names and very precise details about the business process and/or the software. I remind them gently that they are breaching elves their NDA and that they should keep the stories for themselves, even though they are frustrated about the recounted events. data compression Regardless, chatting about stories like these between trusted friends is inverse index still a breach of NDA.