Saturday, November 20, 2010

Linux USB Thumb Drives with no partition table.

Stumbled on this today: USB thumb drives that appear to work fine under Windows, but look like they have a bad partition table under Linux, actually have no partition table, the file system is using the whole device. So to use it mount the whole device /dev/sdd instead of a partition number like /dev/sdd1.

I instinctively typed "mount /dev/sdd1 /mnt/foo", and got the message "mount: you must specify the filesystem type". This usually means mount couldn't automatically figure out what type of file system it is and gave up. I tried 'fdisk -l /dev/sdd' to try to figure out the file system type and got back a very broken partition table though fdisk did give a warking "This doesn't look like a partition table. Probably you selected the wrong device."

Perhaps some of the nice graphical desktop stuff already knows this and does the right thing. Since the file system data can be random it can appear to have a partition table, but will be a completely bogus one.

On closer inspection, the kernel/udev, have only created a device for the whole disk since the partition table didn't look valid, so basically Linux mount, instead of saying "file not found", says, "you must specify the filesystem type". Great, Thanks, that was helpful.

Hope This Helps (somebody else)

Monday, October 25, 2010

Infrared Remote Control:: Introduction

Infrared Remote Control, Consumer IR, or just often IR, the system used in consumer electronics for a remote control to communicate wirelessly with a device. It is interesting to me (and apparently others) because it is the intersection of electronics, wireless, digital signals, software, and home automation. The more trendy and more general term for home automation now is physical computing. Physical computing is a trendy new buzz word, but it is actually a very appropriate description for what interests me. The ability to send and/or receive consumer IR signals allows one to control common electronics stuff with software or allows your software to be controlled from hand held remotes. For example, when using a computer as a music or video player to replace a (CD, DVD, record, etc) player, there are times when it's more convenient to use a small handheld remote to control it rather than a keyboard / mouse. On the other hand since my computer is connected to the audio receiver, when I'm in front of the computer, I'd like to be have the receiver turn on and have it switch the right input when I'm in front of the computer and tell it to "play". Of course there are many more possibilities than this.

Some people's interest and involvement with IR Remote Control centers around building the one remote to rule them all. If you are looking for information about universal remotes, check out,, and google JP1. There has been a lot of good work done in this area, especially the JP1 world, on understanding and documenting the IR protocols in use by the consumer electronics world.

There are many devices and schemes people have come up with for capturing, recognizing and replaying a particular remote signal with a computer. LIRC, Linux Infrared Control is probably the most widely known example. There is also a bunch of closed source software and hardware that are popular for windows environments and in particular the HTPC (Home Theater PC) communities.

When I first started looking at IR remote control, there didn't seem to be very much in good introductory materials. In the last year or two that changed. In my mind one of the big contributors to that is the Arduino, which has been bringing microcontrollers to the masses.

I found that many of the tutorials had gaps or were overly restrictive in their perspectives. It also struck me that there was a significant body of work in the JP1 world, that doesn't seem to be used by the automation / physical computer world.

So I'm hoping to fill in some of the gaps.

Friday, May 7, 2010

Edward Tutfte's Books.

I don't think I can say anything about  Edward Tufte's books that hasn't already been said.   The reviews are glowing. The best way to get all four books is to take the one day seminar, Presenting Data and Information, they are included in the price.   Here are the usual amazon links:

If you take the course or read the books, let me know what your thoughts are.


Thursday, May 6, 2010

Met Edware Tufte this evening

I was out this evening walking my dog headed to the dog run near Chelsea piers.   I had seen on previous walks that Edward Tufte was doing an art installation at the corner of 20th St. & 11th ave. (map)  (NYC's "west" Chelsea area is now packed with galleries.)   There's a sign on the door that says artist tours are available while they are doing the installation, and dogs are welcome.

Today, I stopped to check the sign to see if there was any update on when the exhibit would open.  He saw me opened the door and invited me (and Winston) in.

I had first found out about Edward Tufte's work, in particular his books and one day seminars from Marc Donner.  (If there is anyone I would call a mentor, it would be Marc, but that's another story.)  I attended the seminar I think in spring of '96 or '97 at best as I can recall.  (Marc and I were still at UBS, and it was still Union Bank of Switzerland, pre-Swiss Bank merger.)  Marc took the seminar with me.  It was at Caroline's Comedy Cub which is (or was) very close to Morgan Stanley's building where they put all of the IT people. (This building is often called "the black setback" due to it's design.)

The seminar was fascinating.  There was so much to think about and absorb, I'm sure I missed a significant portion of the content.  I've been meaning to take it again some time. I recommend the seminar to anyone who has an interest in presenting data or trying to see through what others are presenting.   The books are excellent but that's a topic in itself.

If you get to Chelsea stop by the gallery.

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(Hey this post is rambling enough, that it really qualifies as a blog entry)

Wednesday, May 5, 2010

Dusting off this blogger account.

I'm dusting off this blogger account and considering posting some things. Some of the things I want to post should really go in a content management system or wiki, so they can be edited over time and always contain the most up to date and concise information..

I've developed a strong distaste for forums, forum threads, and the people who abuse them to the exclusion of all other types of on-line collaboration. The signal to noise ratio is very low, with all of the me-too posts and the wannabes who don't post original content but further pollute the thread by answering people's questions with "you should read the whole 237 page thread here before asking any questions." If half of that effort was put into maintaining an FAQ, or updating a wiki, we wouldn't have to fight about now, would we?

Ok, so this is turning into a blog style post. One of the reasons I'm considering posting some things to this or another blog is to get some things posted that I admit I'd probably never get around to organizing in a nice wiki someplace.

Is it still a wiki if only one person has edit privileges?

Of course, I think the ideal would be communities of mostly trusted people to be able to collaborate on the content. I've been meaning to try to start one for probably ten years now.

I'm going to post this now, especially because I want to test the ability to come back and edit later.  Ok, I've edited this.  I should see what that does to the RSS.