Archive for the ‘Urban Nomad Computing’ Category

Disappearing Checked Off Items

Tuesday, May 31st, 2011

My workload is largely task driven (as opposed to appointment driven like a family doctor).  So I use a number of TODO lists – on my smartphone and on my computer.  One thing that bugs me is tasks that disappear when checked off.  Poof, all my work disappears and is unacknowledged.  Bad for us workaholics trying to stay in recovery.  And given the vagueness of gestures on touchscreen devices, not nice.  Several times I have had to go digging through the completed items to uncheck a wrong selection.

One of the weaknesses of Amethyst’s UI is short titled articles may lead to errors on clicking the correct delete box.  So now delete boxes on articles don’t immediately banish the article. It will be lined out.  Clicking the box again will undelete it.

And I’m working on a better solution to matching up short titles with their delete box besides alternating color bars.

Real Life Mirrors Internet

Wednesday, March 30th, 2011

I live in Austin, TX, just off West 6th Street.  East 6th Street is the Live Music Capitol, “Entertainment District”.  This means about what it did 100 years ago: live music, alcohol and other recreational drugs, prostitution, and occasional bits of violence.  In the last year or so, West 6th Street is becoming more like East 6th Street.  The neighborhood is going downhill and we are looking to move.

Amethyst, my smart Web RSS reader, is hosted on Amazon’s Web Services (AWS), AKA The Cloud.  Sending e-mail from the cloud is a problem, many domains will not accept e-mail from IP addresses in the AWS range.  So I relay e-mail through where this blog is hosted.  It’s worked fine for a year and a half.  Until last month.  Every startup has a bunch of fires to put out and this one wasn’t the tallest.  It took a month to put out the bigger fires.  Outgoing e-mails were rejected with a “451 Temporary problem, try again later” message.  Same message on the retries.  I tried sending some test messages by hand (via telnet).  One session revealed the real reason, the hosting company has started rejecting e-mail from sites listed in Spamhaus’ Policy Block List, which lists AWS’s Elastic IP (static) and regular dynamic IP addresses.  The hosting company ise working on whitelisting the Amethyst IP address. The neighborhood is going downhill and I’d rather not move.

There More Than One Thing It’s Good For

Monday, April 19th, 2010

Riffing on Perl’s “There’s more than one way to do it.”  Recently I was traveling in California and in one B&B, Firefox worked, but several other applications did not.  I know that Firefox does its own DNS lookups.  The command line utilities nslookup and dig also work and pretty clearly are calling the DNS server directly.  I think the common factor of the failing apps was that they call getaddrinfo().

In a recent Linux Journal, a reader wrote that his solution to untrusted DNS servers when he traveled was to lookup the IP addresses for several key sites while in a trusted environment and copy the results into /etc/hosts (IIRC, LMHOSTS in Windows).  Several Man In The Middle (MitM) attacks rely on compromised DNS servers.

Remembering his workaround, I did the same for Twitter and my RSS reader application, AmethystRSS.net. Worked like a charm.

I’m still working out why domain names did not resolve properly.  DNS resolution worked fine on previous visits and may be fixed by the next visit, but thanks to other members of the OpenSuSE mailing list, I have some problematic areas to look at.  I expect to stay at the B&B again in August.

I’ve noticed that Linux DHCP clients tend to be a little brittle or picky. At a motel in San Antonio, I have to set the default route by hand. My brother’s Mac laptop didn’t have any problems.

bzhive – Another One Bites the Dust

Monday, April 12th, 2010

I dropped by  bzhive.com, a coworking space just north of San Francisco, to check it out.  The door was locked, the lights were out, and nobody appeared to be home.  I called the phone number listed.  A young woman hesitantly answered.  After hearing why I called, she said they were about to or just had announced the closing of the space.

My wife and I walked around the neighborhood.  My first programming job 37 years ago was just two blocks away.  The area was and still is a light industrial park: auto repair shops, a couple of sandwich shops, some glass repair shops, Mighty Leaf Tea company, office spaces, etc.  I think it was a good choice of location – minutes off the freeway, places to eat, parking, and almost certainly cheap rent.  There were a lot of “for lease signs” around.  The landscaping is being kept up.  It is a good neighborhood.

We have been looking around, Marin County is both the old money and the not yet affluent.  The old Italian construction companies are increasingly staffed by Hispanics.  The children of the company founders are off doing something else.  We have not seen an entrepreneurial, techie crowd here.  No coffee houses full of laptops and budding startups.

There are several places like that in Austin, though they are wearing out their welcome and moving into coworking spaces.  Coffeehouse owners are noticing that a business meeting that takes up half their tables for four hours and buys two coffees is not good for their bottom line.  The Starbucks on Anderson Lane has pulled their big table out.  Kneaded Pleasures on Far West bans laptops during lunchtime.  I’ve read interviews with the owners of Progress Cafe in East Austin where they talked about doing the same, or at least turning off the WiFi during lunch.

Duty Cycle isn’t Panacea

Tuesday, July 22nd, 2008

I wrote Duty Cycle to throttle back CPU intensive programs that boost my laptop’s temperatures beyond what I was comfortable with.  It works fine for kernel builds and most other things I tried it on.

Lately I’ve been making some changes to Amethyst, a Ruby on Rails app, that require significant changes to the database — changing the primary key of some tables, merging all uppercase/lowercase versions of a word into a single record, etc.  Guess what, some of the table have 1/3 million records and the changes take time and CPU power, i.e., the laptop heats up.  So I killed the conversion program, and restarted it with Duty Cycle’s default 50% duty cycle.  The CPU usage drops from 99% to 98%!  Huh!  Oh, the conversion program is being throttled by Duty Cycle, but it’s mostly making calls to the MySQL database server which is doing most of the CPU intensive work.  Cutting the duty cycle back to 5% still loads the system significantly, but the temperature stays under 70°C.

Installing Garnet VM apps via Web Server.

Monday, May 19th, 2008

The recommended way to install applications in the Garnet VM (Palm Pilot virtual machine) is with an SD card. I don’t have one, am cheap and don’t want to buy one, and don’t have an SD card reader. So I tried another way that works. Downloading the application files (.prc and .pdb file) from a Web server. In my case I just down loaded them from a Web site such as Freeware Palm, uncompressed or unzipped as needed, and moved the files to the public directory of a Web server on my laptop. From there I just plugged in the URL into the browser on the Nokia and downloaded them. The installation in Garnet VM is just like applications installed via an SD card, just from a different location in the Nokia.

Nokia N810 and Garnet VM

Monday, May 19th, 2008

I was a bit surprised how few applications there are for the N810.  My plan was to replace an aging Handspring Visor.  There just aren’t the apps to do that yet.  I’m going to write some Real Soon Now, just as soon as I wrap up some Ruby on Rails app releases.

There is a Palm Pilot Virtual Machine, Garnet VM.  It is in beta and supports only some Palm OS applications.  I am digging through the apps I have on the Handspring, but most won’t install.  So I’m trying to find free/cheap equivalents that will.  So far Teapot seems to be an acceptable replacement for Toast Timer to time meditation sessions and watering sessions.

Nokia N810 – GPS

Wednesday, February 13th, 2008

The GPS receiver in the Nokia N810 isn’t very strong.  I have yet to get a position fix indoors or even in a car.  Outdoors it does acquire position fixes, but there is a fair amount of uncertainty/jitter.  Standing still my “position” wanders about.  It is good enough to figure out which block in a city your are on and even which end if it isn’t a tiny block.  The maps in the database are low resolution, i.e., line segments, not smooth curves.  The Points of Interest (POI) are sometimes out of date (e.g., restaurants that have closed).  Only roads are included, no footpaths, so not very useful for hiking with the included maps.  (Is there a source somewhere for the USGS topographic maps?)

DutyCycle on SourceForge.net

Thursday, January 31st, 2008

DutyCycle is now feature complete and is a SourceForge.net project. There is a source tarball in the download section and all files are checked into version control (CVS). Today I added signal propagation so interrupting dutycycle interrupts the controlled program and switched from usleep() to nanosleep() for finer time slices.

City of Austin WiFi mesh blocks outgoing mail

Tuesday, January 29th, 2008

The City of Austin has a free WiFi mesh network around City Hall, Republic Square, and East Austin. Fine for browsing reading e-mail via IMAP or Webmail, but it blocks outgoing connections to an SMTP server on port 26. Boo. Port 25 is standard but frequently blocked. My Web & e-mail hosting company also makes the SMTP server available on port 26 to work around this.  Several other WiFi hotspots downtown do this also.

The e-mail client on the Nokia N810 is turning out to be less useful than expected.