first CAD lesson

There are several FOSS (free / open source) CAD programs in linux.  The main ones appear to be LibreCAD for 2D and FreeCAD for 3d.

I chose FreeCAD and did the basic part design tutorial.  It teaches first things  like constraints, extrusion from 2D to 3D, Continue reading


Virtualbox XP guest crashing on Arch

My XP virtual worked fine under Debian for various R/C simulators.

I really hadn’t been playing with it since going to Arch but the virtuals were crashing (“Aborted”) whenever video drawing got complex. Hmmm.

I jacked with every setting that looked promising in VB, BIOS, etc.  Then I checked my video driver.  Ahhh….
Arch was using the Nouveau driver, the open source default driver for nVidia cards.  Arch was running everything so snappy I didn’t think about loading the nVidia drivers. I stuffed the legacy drivers for the GeForce 210 in there and virtualbox seems to be much happier.

sudo pacman -S nvidia-340xx

700MB of manpage pre-processor?


Building Tor has failed since manpages cannot be built.

You need asciidoc installed to be able to build the manpages.
To build without manpages, use the –disable-asciidoc argument
when calling configure.

Fine, whatever.

sudo apt-get install asciidoc

Reading package lists… Done
Building dependency tree
Reading state information… Done
The following extra packages will be installed:
dblatex docbook docbook-dsssl docbook-utils docbook-xml docbook-xsl fonts-droid ruby1.9.1-dev ruby-switch

perlsgml w3-recs tcl-tclreadline texlive-doc-en perl-tk purifyeps chktex latexmk dvipng xindy dvidvi fragmaster lacheck latexdiff psutils t1utils libfile-which-

Need to get 699 MB of archives.
After this operation, 1,121 MB of additional disk space will be used.

Uhhhhh, no.

./configure --disable-asciidoc argument

For 700MB of diskspace I am willing to google man pages.


virtuals and containers

I have been using qemu and, increasingly, virtualbox to run various OS experiments.  I also run the OEM XP that came on my workstation in a virtualbox instance on that same workstation;  a demotion of sorts I suppose.  I run R/C aircraft training simulators on XP as it is much cheaper to hit RESTART than to rebuild aircraft.

In the last couple of years I’ve been hearing more about containers as a potentially lighter-weight solution to problems that might have been solved using virtualization before.

Still getting my head wrapped around the container model, but I started a couple of small test containers for running some CLI utilities (screen and mosh, as it happens).  I was reassured to see that adding a 2nd and 3rd Debian-based container required only a few bits of data pulled down to support the new utilities.  I think this is supposed to be a major feature but it’s always good to see something for oneself.


< hello, whale >
                    ##        .            
              ## ## ##       ==            
           ## ## ## ##      ===            
       /""""""""""""""""___/ ===        
  ~~~ {~~ ~~~~ ~~~ ~~~~ ~~ ~ /  ===- ~~~   
       \______ o          __/            
        \    \        __/             


x11vnc v. x0vncserver

I use a VNC server to access the GUI when an SSH terminal session doesn’t suffice.

Under Debian I’d been using x11vnc but it has been unstable under Arch.  Frequent buffer crashes, particularly when the whole screen changes or I right- or middle-click the mouse.  Annoying, and I hadn’t had any luck fixing it.

I have some interest in playing with FreeNX/NoMachine, but I haven’t found a portable Win* binary.

So I went back and took another pass at tigervnc, a tightvnc fork,  whose server binary on *nix is called x0vncserver.  The command line args are a bit different so I had to (gasp) read the man pages.

It was worth it.  the TigerVNC server is significantly faster than x11vnc.  I don’t have to run the blotchy 64-color palette to have decent response over my slow upload “broadband” ssh tunnel.  And no crashes no matter how I stress test it.

Pi scanner project: solar powered

The Raspberry Pi 2 B is up and running on solar power:
 photo 20160225_204803_zpscbptjgyo.jpg

The laptop that does scanner audio process is dying and the Pi will (hopefully) take its place.   A 3A DC-DC converter steps the nominal 12vdc down to 5vdc.  The power runs into the hub on the right and I also use it for charging phones and the like.

For the curious:  this is a 45w Harbor Freight setup feeding a 12v deep cycle battery.  I’ve also got a 60w panel and a couple other controllers but they aren’t being used at the moment.