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Engineering & Code

Engineering & Code explores the full stack of modern tech—from bits and transistors to cloud fleets and formal proofs. Here you’ll find clear, rigorous walk-throughs of software design, embedded hardware, security architecture, and the physics that underpins them, always paired with code, schematics, and reasoning you can put to work.

Convert avi’s, mkv etc to the iphone

Handbrake is amazing with active development and a great community. When I wanted to transfer a bunch of lectures to iphone/ipod touch format, I faced the time-consuming challenge of converting a hundred files using the Handbrake gui and figuring out the complicated set of options for HandbrakeCLI — their nightly build standalone. So, here is […] read more

Recovering Rails Data Using Production.log

So you didn’t set up automatic backups and need to recover your data? Don’t try digging it out of mysql, look no further than your rails production log. OK, try a bit with mysql, because the rails production log is a terrible way to recover your data. Only use as a last resort, but when […] read more

MacBook Local Link Address — can it be fixed?

I have a bad, bad networking problem with my wife’s MacBook. She can’t connect to the internet anywhere, but I am working with my Netgear WNDR3300 for this problem. Our wireless router is dd-wrt based (open source router firmware), and works fine for about 20 other nodes (other laptops, guests, mobile devices, etc). A couple […] read more

Building Plots in Visio

I like to automate Microsoft Visio to draw plots. They look so much more professional and I don’t have to fuss with Excel to figure out how to make plots look like I want. Again, this is me practicing my theory of being in control, not letting software control us. Please let me know if […] read more

Congressional District GIS Exploration

MathJax.Hub.Config({tex2jax: {inlineMath: [[‘$’,’$’], [‘(‘,’)’]]}}); I wanted to be able to do this with my ip address: I do development and consulting in two areas I really love: fitness and political engagement. For some work I’m doing on the latter, I needed to figure out the latitude and longitude of the geographic center for each of […] read more

Paperless Archive Makeover — ruby and unix to the rescue

I recently had to clean out my digital paperless archive — a task made much more difficult by encrypted PDFs and a bunch of lint in my directory. We have been paperless since 2001 and have many gigs of files in a hierarchical file structure that was becoming difficult to use and maintain. (i.e. Where […] read more

Generating PDF files with RTeX

I love LaTeX and I love ruby/rails. I want to use rtex, it seems perfect for me. But, I am having trouble and am looking for help — once i get this working i’ll make a blog post for the world. First, do i have what it takes? tim@polycarp:~/test_rails$ which pdflatex /usr/bin/pdflatex tim@polycarp:~/test_rails$ which latex […] read more

pdf rtex

I love LaTeX and I love ruby/rails. I want to use rtex, it seems perfect for me. But, I am having trouble and am looking for help — once i get this working i’ll make a blog post for the world. First, do i have what it takes? Now I need a rails app to […] read more