Preparing The Roach Palace for Halloween

It's right around the corner, and here's what we're doing with the place. First, the Keykeeper moved the security camera so it can see out further and maybe catch some pumpkin smashing hooligans in the act. (We're not going to be turning them in or anything like that--this is only for curiosity!)

Secondly, I'm preparing a computer-driven lighting effects system with X10 home automation stuff that I picked up a long long time ago and have used for various tasks since then.

And finally, an IBM PS/2 Model 57slc makes a brief appearance in this video as the ActiveHome controller PC.

Category:

Science & Technology

Tags:

• computer
• IBM
• PS/2
• Model
• 57SLC
• ActiveHome
• X10
• automatiion
• electronics
• camera
• halloween
• The
• Roach
• Palace

[StarCar98]

I'm a little techno stupid here, but why does a TV or a computer monitor always have those bars rolling through it, like when an old TV has the vertical hold out of wack., when you take a video of it?

[uxwbill]

It has to do with the refresh rate of a TV or monitor. The picture on a TV or monitor is not really as it appears to us--it is actually the result of the very rapid movement of an electron beam (three for color displays) across the screen (vertical and horizontal). That is called deflection and it lights up the phosphors in the tube face. These have persistence and will stay lit for a while.

Our eyes see a complete image, while a camera sees a result closer to what is really happening.

[uxwbill]

The camera won't just see the moving line, because while its response time is faster than that of our eyes, it's nowhere near as fast as that electron beam is moving inside the picture tube. Instead, it will see a sort of combination--some of the picture AND a "flicker" or moving line.

The effect is less noticeable when a camera is pointed at a TV, because most TVs use an interlaced scanning method where all odd and then even lines are drawn, which gives less "flicker".

[uxwbill]

(The fact that the TV--at least for NTSC TV in the US--is running at a total frame rate close to what the camera is recording may also result in less apparent flicker or scanning in the recorded video.)

Computer monitors are typically scanned in a progressive, or non-interlaced method, where each picture line is drawn one right after the other, to the bottom of the screen. And the refresh rate is much higher than that of nearly any TV standard--usually at least 75Hz (times per second) vertical.

[StarCar98]

phosphors...is this the gas in the TV tube like a flurescent bulb and when you charge it with electricity the molucels get excited and start moving around rela quick and start crashes into each other and put off light ??

[uxwbill]

There's no gas in a conventional picture tube. It's a vacuum in there, with a "getter" that soaks up gasses that were not removed when the vacuum was pulled.

The phosphors are actually light emitting material painted on a thin metal screen at the inner front of the tube. When the electron beam strikes a phosphor it is excited and glows as a result. Do this fast enough with the beam, and you get the apperance of a full picture.

[StarCar98]

Thanks Bill, I'm 42 and was just shown that if I press this blue fn button and this other button I can make the screen brighter so I can see it better. I guess my wife was right, I can chain 44,000 pounds of machinery down and go screaming off the side of a mountain at 70 mph and it doesn't faze me but the little things in life still amaze me sometimes. LOL

[uxwbill]

I have some of the IBM branded stuff as well. IBM had their own branded version of the X10 control software that they called "Home Director". I think it was actually sold as an option with some Aptiva computer systems.

[uxwbill]

Yes we did.

[moldymac]

I didn't know that software could do that! I have the old X10 stuff before they ruined the name. Mine is all IBM branded. I use to use it for my home theatre to adjust lights. It also came in handy for christmas lights. One command turns it all on, another off.