High Speed Movies from a Point and Shoot

casio-exilim-fs100I recently purchased a Casio Exilim FS100 point and shoot camera. At first glance, there’s nothing remarkable about this camera. It’s not too incredibly tiny, doesn’t boast a zillion megapizels nor a battery that lasts for 24 hours.

What it does offer though is the ability to shoot high speed movies from 240fps up to 1,000fps! Below are some example shots of the movies that I recorded. Both movies were shot at 240fps.

The camera is available at Amazon.com for $220 (including a $30 price break until November 28, 2009).

Commodore 1520 Printer Plotter

NOTE! Split gears causing causing or plot errors? New replacement Alps gears for the Commodore 1520, Atari 1020, etc are now available! Click here to order your set.

Commodore 1520 Printer PlotterMy first computer was a Commodore VIC-20. I got it as a Christmas present from my parents in 1982. I’m pretty sure they picked it up at Montgomery Ward, which was still around at the time. Shortly there after, I got my first printer to go with it. A Commodore 1520 Printer Plotter.

Commodore 1520 PensThis printer was great. Firstly, it was tiny for a printer. It was smaller than the computer! Everything about it was tiny. It used tiny 4.5″ wide paper that was on a roll. It used tiny ball-point pens (yes, pens!) of four colors that it could selectively choose. I used it well, mostly printing nonsense I’m sure. Time passes and the printer disappears. I think I may have “taken it apart” which for me at that time usually meant destroying it. In any case, the original never followed me.

Fast forward to 2001 when I bought two from eBay. One came with the box and some extra pens (which proved to be the most elusive consumable). But irritatingly, the printer seemed to have fits when it was asked to print something. The motors would make an unpleasant noise and the print head would vibrate in place. The paper advance was also acting up.

Commodore 1520 GearUpon further inspection and some help from the interwebs, I found the culprit. A very tiny gear connects the stepper motor to the rest of the gearing to move both in the X (print head left and right) and Y (paper up and down). These two gears, made of nylon or plastic, have shrunk over time and split, causing the teeth of the gear to get jammed. Commodore sourced the plotter mechanism from ALPS (as did Tandy, Atari and Mattel for their plotters). Likely all plotters using this mechanism are suffering the same fate. Frustrated, I shelved it.

Fast forward to 2009 when I take a course in historical computers, I decided to revisit the printer to see if I can repair it. I found a terrific resource on a Commodore 128 forum from user “airship” he calls The 1520 Plotter Survival Guide written in 2007. It lists sources for the paper, the pens and possible help in fixing the gears.

ALPS Plotter MechsTo fix the gear issue, I decide to take the repair route. A company called Electronic Goldmine has the ALPS plotter mechanism (surplus) that Commodore used (at $1.49 ea!). I buy 10, hoping that at least a couple of the gears will be good. All of the gears are split– time has not been good to them. But the good news is the mechanisms make great replacements if the original motors are bad. Plus it gives me 20 gears to try and fix various ways.

To repair the gears, I first remove them from the stepper motor. They’re just pressure fitted so they slide off. I used some super glue to fix the split back together and clamp it together overnight. I then use a 1/16″ drill bit to drill out a tiny amount of the center of the gear. This will relieve the strain and prevent further splitting when the gear is back on the motor shaft. Next, I dry test the gear on the motor and see if it works. If it does, I use super glue to attach the gear to the shaft.

The result:

It works! I keyed in a demo program from the manual and produced this:
Commodore 1520 Geometric Design Plot
Coming up in another post I’ll show you what it looks like when it plots text (with slow motion video).

NOTE! Split gears causing causing or plot errors? New replacement Alps gears for the Commodore 1520, Atari 1020, etc are now available! Click here to order your set.

VHS Erasing Project

VHS ErasingI’ve been cleaning house lately. One thing on the chopping block was my massive collection of VHS tapes that I’ve accumulated over the years. Since they’ve been stashed in the basement and I haven’t needed anything from the collection in several years, I decided it was time to part with it.

But, as with any media, you should wipe it first. Sure, I could use a bulk eraser (which I have access to). The problem is they are not 100% effective. You get a sine-wave affect on picture clarity usually. Plus they make an unholy sound when running, tend to smell from the heat and cause chew up electricity rapidly. I also read that big magnets from speakers are effective.

But the only way to be 100% sure is to stripe them. So I’ve acquired a few VHS decks (they’re not hard to find, look under “Good Will” as they are currently overrun with them, having been kicked out of the living room by DVD– don’t worry, you’re next DVD). The decks will now serve to erase my whole collection. And they’ll most likely never play another tape again when it’s through.

After that, maybe to the Good Will, or maybe I’ll glue them together into a chair. If it’s worth doing, it’s worth overdoing.