Fighting with computers

Computers are not always friendly.

Tuesday, March 31, 2009

Iomega Screenplay Pro HD hacks

I was not sure what gift I would get for Father's day. A colleague of mine was very happy with his last gadget, a multimedia hard disk that could reproduce High Definition content from its 1TB disk and it could also record from a video input.

I already own one (older) version of that (Freecom Media Player) so I was not impressed with the idea, but my friend insisted I should try his unit at home.

I brought the system and I hooked it to TV. I tried some HD content I had around and I liked what I saw, so I was sold. I would be replacing my TV computer whose SAT receiver card is no longer in use as I switched to a cable provider years ago. Still that computer was serving me well, still with its original SUSE 8.2.

The Iomega unit does have HDMI, components and composite video outputs, plus an optical audio output. It has a host-mode USB socket that accepts external storage (i.e. another hard disk). It can also be connected to a computer by USB (a B-socket in this case) to be used as external storage. Video and audio inputs are by means of another set of RCA sockets, and an external power supply completes the connections. Not to forget the RJ-45 LAN connection that enables both remote playback of files stored in the disk or playing in the unit the files stored in your computer. A third possibility mention in the docs that I haven't tried yet is to play streamed contents throught the network.

The unit is powered by Linux and there is telnet server running, so you can telnet to your box (root user, no password). Files can be transfered either over the network or by attaching the unit to a computer through the USB port. The latter option is way up faster. In fact, the performance of network transfers is depressing at around 2 megabytes per second only.

Given the system is Linux-based and the telnet access is open you imagine there is something you can to change your system (hopefully to improve it). Native filesystem is NTFS but that may be a problem if you want to connect it to Linux PCs. The problem is not to read or write while the NTFS partition is clean. However, first time I tried my friend's unit it would not work. The reason: an abrupt detachment of the unit left the NTFS partition needed for a filesystem check. Unfortunately nor the Iomega system nor a PC running Linux can do that. Problem was fixed by connecting the drive to a Windows PC. After that everything went fine with Linux too.

There is an interesting blog about this device. There is also a nice wiki. Among the changes I've done I can recomend:
  1. Change partition to ext3 (if you main system is not Windows). Or to FAT32 if you use OS X (though FAT32 will limit the maximum size of files to 4GB).
  2. Install a patch so files over 2GB can be transferred over the network.
  3. Install a web-based BitTorrent download system. If you do that you'll want to have some swap space (I used a swapfile on the hard disk).
  4. Install a toolchain so you can compile your own programs.
There are many more ideas on the wiki mentioned above so if you own this cool system you can experiment with the many changes proposed.

At 199 Euros in PC-city it is a steal! You can use binaries from OpenWRT project too! Can you guess what gift I've got for Father's day?

Sunday, March 29, 2009

Electronic magazines "made it simple"

A few years ago I was excited when Zinio started (what was to me) a new business: Electronic magazines you can download and see them in your computer display. Zinio model required a DRM-ed software on your computer and Internet access to double-check the binary file you've stored in your computer was one you're entitled to see.

Platform-dependent and not so flexible made me walk away from Zinio. However, for a number of years I've been a paying subscriber of Circuit Cellar magazine whose model was, IMHO, simpler and better: a PDF file.

Today I've learned that this magazine (that sometimes has featured articles by me) is adding (not moving) a new flavor for their electronic version. One version powered by Mymaganizes.net, that in essence is a Flash-based viewer similar to the one at Issuu. I guess that besides free content the company also manages users subscriptions.

By checking on-line I can see that now Zinio has also enabled a browser-based reader that does not required the user to install any software (it was not like that a few years ago).

And, by the way, it really helps when you have a really big display :-)

Monday, March 23, 2009

Modbus/TCP


A recent project I'm working on needs to behave as a Modbus slave. Not that Modbus is a complex protocol, but it is always handy if you can save yourself the effort of doing your own implementation. After some trouble I've got FreeModbus library up and running.

While looking around I've also found some cool tools like modpoll that can allow you query a Modbus slave. And while I had some trouble with the Linux binary (libstdc++5 was missing), the Windows binary runs happily under wine too. Another great set of tools are these ones. You can even connect your Excel spreadsheet to values obtained from a remote slave!

It was fun to realize there is even a Modbus for Arduino implementation.

Sunday, March 22, 2009

Tidying up your photo/songs collection


Over the years and hard disk changes and backups and new computers and OS installs I've got a pretty untidy photo collection, scattered across several disks.

I wanted to make a clean and tidy library on my main desktop using F-Spot. Unfortunately this program does not have yet a duplicate detection feature (it seems to be available in the latest version though). So I've ended up with many photos repeated on my new library after importing from different backup copies.

I thought I could do a simple script to find those files with matching md5sum, no matter the filename, so I could remove the photos that appear more than once. But I was glad to see that somebody did it first.

Of course the same idea could be applied to MP3 files or any other type of file. The only drawback, if you want to be picky, is that md5sum covers the whole data of a file, so a change in let's day EXIF data in a JPEG file will render the file as different even though it may contain a duplicate image. Same holds for two identical MP3 audio files with different ID3 tags. A better mouse trap would ignore the metadata on the files.

Tuesday, March 10, 2009

Slidecast = Slideshare + podcast

It's not new. It's not original but it seems to me the easiest way to put together some audio with a synchronized slideshow. I mentioned Slideshare three years ago, but now I've learned they offer a cool on-line service (no software to install on your computer) to create synchronized-audio slides.