Backscratcher And Safecracking

Henry had to make an invention as a school project. He decided to make a Minecraft inspired backscratcher.


Henry sanding. Notice the safety footwear.

The finished product. He did 90% of the work although I helped him use the bandsaw.

In action.

I bought this locked fire safe for $2.00 (marked down from $3.00) at a yard sale today. Who knows what’s in it? The person giving the sale said she didn’t know. It weighs 45 lbs so it must be full of gold, pistols and diamonds with a few bearer bonds for good measure.

I tried to crack it by turning the dial and listening but couldn’t get anywhere.

2 minutes with prybars and it’s open.

Oh well. A single CD containing someone’s backup data from 2006 with instructions for burning a CD. This is why I don’t play the lottery.

Accumulated Links

Just a dump of stuff I consider interesting from the past couple of months.

• viSparsh Haptic product development.
• YUMI Multiboot USB Creator. I now has a USB thumb drive set up to boot into one of several Linux distributions which is handy and fun. Still haven’t gotten it to work well with distributions other than those directly supported, but that’s probably my fault.
• Ancient Computers in use today.
• Reel Crime: The Pulse Sensor Counterfeit LEDs Story
• Mastodon bones found at (Corvallis) construction site.
• The Oughtred Society, crazy slide rule collectors.
• ViewPlus makes braille printers in Corvallis.
• SPARK Museum of Electrical Innovation, need to visit it!
• MIT App Inventor is now in open Beta. I played with it a little, it seems like a good way to teach Android App development to kids already familiar with Scratch.
• Circuit Lab simulator. Haven’t played with it yet.
• Japanese Fart Scrolls
• E-Asia Digital Library at U of O.
• SciShow on Youtube.
• Open Beam, a friend is launching an Open Source miniature construction system (t-slot extrusion) that looks much better than the alternatives.
• Sonic Screwdriver TV-B-Gone, just met the chap that made this Instructable.
• Zack Henningsgaard Photography. The son of a friend has just started his first business. Great work and how the hell am I so old that kids I knew as babies are now adults?

Timex Sinclair ZX81, My First Home Computer

I brought my Timex Sinclair ZX81 back from my visit out East.
My dad bought it in 1982, It was $99.95!

Tiny with a flat membrane keyboard.

The 16K RAM pack. It has 1K onboard.

The video cable, not a composite, but a UHF signal.

I tried to use the adapter on the right with a cable, but it didn’t work. My EE on call suggested the impedance was wrong. So I soldered up this cable from a coax and an RCA plug.

I think there’s probably a better shielded solution out there.

Feeding it into an old ATI All-in-Wonder AGP card in a P4 box through the CATV jack.

I had to play with the settings, pumping up both brightness and contrast.

The ancient ATI software sucks. This actually looked a tiny bit better on screen. I think there’s a lot of noise in my system. But it’s legible. Here are some videos I captured:

• Hello World
• Simple For Loop
• Sine Plot

The confusing membrane keyboard. You try and figure it out.

16K Ram pack installed.

No output at all. Must be bad.

I have some software!

Wrap your head around this.

I have reference material. The Z80 book was a birthday gift. I did a lot of PEEKing and POKEing.

Why not open it up? Two slotted screws on one side, two Phillips on the other.

Opened.

Some insulating card stock.

Other half.

I don’t know what it is. Could just be fluff, but it could be from the capacitor.

One board.

The other. Connected with a ribbon cable.

That fluff. What is it?

Removed, it may not be anything. But maybe I’ll replace that cap? We’ll see, I want to do a little reading.

This might be my new desktop wallpaper.