Rick’s Rants and Raves

There is a lot of noise about how slow the NSLU2 is. The real question is, Is it fast enough to do the things you want to do? I present as an example that the NSLU2 is “fast enough” this situation:

• One of my computers was downloading some large files to the NSLU2′s drives taking up my full DSL bandwidth.
• Simultaneously, on another computer I was watching a video that had been previously stored on the NSLU2. It was a 42 minute video, at roughly 350MB. There were no hiccups or interruptions.

What is the total bandwidth of these two activities? Who cares!?! The point is that it did what I needed it to do.

While I was playing with hard drives, I was really struck by how mirror-like the platter surface was. I decided my next project was to create a “mirror” out of hard drive platters.

So I started asking around for “dead” hard drives. I know there must be mountains of them out there. I hit pay dirt when one of the server dudes at work said “Yeah, you can have all of them out of this MSA.” He handed me 10 18 GB drives (worthless on eBay, I checked). Along with the others I had amassed, I figured I had the raw materials to begin.

I then completely gutted them all, saving every single part. A couple of challenges that I encountered:

• A lot of them required multiple sizes of Torx bits. The ones I had on hand were not enough, so I picked up a set that included 5mm through 10mm. With those in hand, almost nothing stopped me (see next…)
• My technique for removing the top ring around the drive motor was clearly flawed. No matter how many I took apart, I stripped the head of the last screw I had to remove. This really sucked. I had to drill out the head of the remaining screw to get the platters off. It clearly had something to do with the pressure exerted on the remaining screw by the platters, but no matter how carefully I worked them out, the last one’s head stripped. I broke at least one drill bit during this process.
• I could not get the drive motor out of most of the ones given to me by my coworker. They were secured by a nut that was set into the case such that I could not get pliers, wrenches or sockets to bite on it. Fortunately I could get one out (different brand) and that was all I needed.

I then played with the pieces of circuit board and other parts to find a layout I liked for the background.

I placed part of the drive tray holders on some plywood (secured with wood screws), then layered the circuit boards on top (secured with hot glue). I was short one drive tray holder to make a complete border, so I took one of the tray levers (used to pull the drive from the MSA) and put it at the top.

The Hard Part

The hard part was figuring out how to secure the drive platters. Glue doesn’t stick to them. I finally decided to use the same technique that the manufacturers did: clamp the platters on the drive motor. I put spacing rings on the motor until I had just enough room for two platters stuck right together. I secured those with the motor’s retaining ring, then started jamming the edges other platters in between the center two platters. The result is kind of like a flower, kind of like a mirror. The top platter in the center go so warped by the jammed in platters, that I glued another platter on top of it. Yeah, I know I said glue doesn’t stick–I used a ton of glue and all it has to do is hold the weight of one platter. So far (2 hours) it has held….

Finally, I threw an armature on the edge and we have the final result…

In the end, I used 14 platters. There were 6 platters in each of the 18GB drives, so that means my “mirror” is a total 42 GB. And yes, I’m using the term mirror loosely–I sure as hell won’t be shaving with it….

My digital picture frame continues to work fine, with only one minor hiccup–a board had come loose, preventing it from booting. I took it apart, reseated everything and it worked fine after that. That event reminded me that I almost never turn the darned thing on. Why? because it runs off a stupid hard drive that takes 3 minutes to turn off. So if I have the image set to rotate every 10 minutes, 30% of the time I can hear it. I don’t want to pay attention to it–I want it to just be there, available to be noticed, but not actually drawing my attention when it changes pictures.

Months ago I had become aware that people sold IDE hard drive adapaters for Compact Flash cards. Since I currently possess a 512MB and a 256MB card for a camera that almost never gets used, I figured one could easily be put to use making a completely silent digital picture frame. I did this using Slax (a super clean Linux distribution). Here’s what I did.

Get SLAX

Follow the instructions here to install the files to a compact flash card. I assume that you have a Compact Flash to USB adapter and that it shows up as a drive in your computer. I used the Popcorn Slax version. Any but the Frodo version should work.
Get Quick Image Viewer

QIV (Quick Image Viewer) is a graphics viewer module specifically for SLAX. Save it to your compact flash card in the \modules directory.

Change Boot Options to Start Xwindows

Open \syslinux.cfg in WordPad (NOT NOTEPAD!) and add “autoexec=startx” to the end of the line that starts out “append”. This was the last line in the file. Just in case, here is what my syslinux.cfg looks like (the append line should all be one line) :

prompt 1
timeout 4
default slax

label slax
kernel vmlinuz
append vga=769 changes=slaxsave.dat probeusb max_loop=255 initrd=initrd.gz init=linuxrc load_ramdisk=1 prompt_ramdisk=0 autoexec=startx ramdisk_size=4444 root=/dev/ram0 rw

QIV Startup Script

(Almost done…) Now we need a script to tell QIV to start up automatically. There may be other ways to do this, but this worked for me. In the \rootcopy folder, create the following directory structure: root\Desktop\Autostart. Inside Autostart, create a file (or use mine) called qiv-start.sh. Here is what I put in the file:

qiv -isrtf -d 300 /boot/photos/

The number (300 in this case) is the number of seconds between photos in the slide show.

Add Your Photos

Create a directory called photos in the root of the compact flash card. DO NOT PUT IT IN THE BOOT DIRECTORY like you might be tempted to because of the qiv command line above. Trust me on this one. When SLAX boots up, the \photos directory will be “mounted” in the /boot directory. If your CF card is E:, put your photos in E:\photos. Seriously.
Put all your photos in the \photos directory. In order to conserve space, I recommend you convert your files to the resolution of your display before copying them. I describe the way I do this in my original post. My 800×600 jpg files ended up being about 150KB each, on average. After using 100MB for the SLAX OS install, that leaves room for 2500 photos on a 500MB CF card.

Plug it in, boot it up

Good luck finding the adapter to make it work for you. In the end, I couldn’t. My laptop picture frame has a funky adapter that I couldn’t identify, but I didn’t figure that out until I’d gone through all the work with the SLAX install. So in the end, I ended up getting a PCMCIA Compact Flash adapter, and putting all the pictures on that. After the system boots up off the hard drive, the slide show runs from the CF card. It is totally silent within 10 minutes of booting.

As I was looking at sites that linked to my Hard Drive Clock I was intrigued to find a Russian site: http://mobbit.info/item/2095. I tried to see if Google language tools would translate the Russian site (specifically the comments), and I noticed that you can view Google in Elmer Fudd. That kind of sense of humor just plain rocks.