When I upgraded to a new laptop, I also upgraded back to a dual head setup with a pair of external monitors. I don’t need the laptop to be sitting in the middle of my desk anymore, so I wanted to find somewhere I could park the laptop, preferably out of sight.

I picked up four larger PVC J hooks from Lowes for less than a dollar each. I’m pretty sure I used the hooks meant for 1.5-inch PVC pipe.

I screwed two of them to the desk with the J side facing down. This makes the floor the laptop sits on. I screwed one more into the desk with the J side facing up. This one keeps the laptop from tipping out of its little cradle.

I cut the third one down to about one third of its original length. I screwed that one into the desk perpendicular to his other three friends, being careful to position it so that it didn’t block any of the ports on that side. His job is to make sure I don’t just slide the laptop straight through, out the back, and onto the floor.

After it was already in place, I realized that it is probably a good idea to have the front hook mounted a tiny bit higher than the rear hook. That way, gravity would hold the laptop up against the smaller hook.

I have a can of black vinyl dye here. My plan is to spray the hooks and my DIY monitor stand black. I’ve been putting it off because I’ll have to take down the monitors and the laptop for a day or two. One problem is that I don’t want to be without my monitor and laptop stands for a few days. The other problem is that I can’t see any of the PVC from where I’m sitting. I barely realize it isn’t painted.

Update 2010-11-06:

I finally got around to spraying the laptop rack with vinyl dye and I added a picture of the finished product. It looks much better now and it doesn’t stand out nearly as much as it did when it was bright white.

After quite a few months we are finally past the planning stage and starting to build something. I am very happy with the progress we are making so far.

We bought two 4’ x 8’ sheets of 5/8” particleboard and had Lowes cut them in half for us to make it easier to transport them home with us. Our quick whiteboard sketches told us we wouldn’t be gaining any useful pieces of board by keeping them whole. We will definitely have no problem at all making the entire cabinet out of these two 4’ x 8’ sheets of particleboard.

Cutting the Slots

Cutting the slots in the boards with the table saw was easier than either of us expected. The first set of slots we cut were extremely snug and it was VERY solid when we assembled it most of the way. We were worried that it would be too hard to disassemble later on if we ever have to move the table, so we cut the slots a bit wider. We took off about half of a saw blade’s worth of material off the outside of each slot.

It slides together much more freely now but it still does a very good job of keeping itself square.

We cut shorter slots in the sides to mount the control panel boards. We probably made two minor mistakes here. We should have cut these slots to be very snug and we didn’t really leave enough room for the slots on the skinnier sides to get much bite. We’ll just end up having to use some screws to keep the control panels in place.

I’m very happy with the progress so far. We have about four hours invested so far. I certainly didn’t expect to get the rough control panel boards cut and fitted so quickly.

The Next Steps

The next time we get a chance to work on it, we will probably be mostly making cuts with a jigsaw, and sanding.

We are going to cut the corners on the control panels round. We also want to cut some curves into the outsides of the “legs.” We think it will look better if it isn’t just a square pound-sign-shaped box.

We are also going to cut out some of the bottom of the box to make a bit of extra room for feet and legs. We aren’t three-and-a half-foot-tall eight-year-old kids eating pizza and playing games in an arcade anymore. Now we’re six-foot-tall adults eating pizza and playing games at home, and we need to be comfortable!

Hopefully we will be able to make time to work on it for another few hours within the next week or two.

I was running btrfs for almost a month before I got around to setting up some automated snapshotting. I was expecting to have to write some scripts of my own, but I luckily I found btrfs-snap. All you have to do is pass btrfs-snap the path of the volume to snapshot, a tag for the snapshot (daily, weekly, etc), and the number of snaphots to keep. It stores the snapshots in a .snapshot directory at the root of the volume and names the snapshots using the tag and a time stamp.

I have mine set up to keep 4 weekly snapshots, 7 daily snapshots, and 24 hourly snapshots. I also tried keeping a dozen five-minute snapshots (fivers). Things got gummed up when I tried that and I had dozens of snapshots processes sitting around idling. I could probably get around that issue by making sure only one snapshot job is running at any given time.

Here’s my cron scripts:

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#! /bin/bash

/usr/local/bin/btrfs-snap / hourly 24
/usr/local/bin/btrfs-snap /home hourly 24
/usr/local/bin/btrfs-snap /home/wonko/wip hourly 24

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#! /bin/bash

/usr/local/bin/btrfs-snap / daily 7
/usr/local/bin/btrfs-snap /home daily 7
/usr/local/bin/btrfs-snap /home/wonko/wip daily 7

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#! /bin/bash

/usr/local/bin/btrfs-snap / weekly 4
/usr/local/bin/btrfs-snap /home weekly 4
/usr/local/bin/btrfs-snap /home/wonko/wip weekly 4

And here is a set of snapshots:

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wonko@zaphod:~$ ls /home/.snapshot
daily_2010-09-04_07:43:13   hourly_2010-09-12_00:17:01
daily_2010-09-05_07:28:22   hourly_2010-09-12_01:17:02
daily_2010-09-06_08:05:00   hourly_2010-09-12_02:17:01
daily_2010-09-09_06:44:39   hourly_2010-09-12_03:17:02
daily_2010-09-10_08:00:54   hourly_2010-09-12_04:17:01
daily_2010-09-11_07:59:08   hourly_2010-09-12_05:17:03
daily_2010-09-12_07:51:40   hourly_2010-09-12_06:17:01
hourly_2010-09-11_13:17:01  hourly_2010-09-12_07:17:01
hourly_2010-09-11_14:17:02  hourly_2010-09-12_08:17:02
hourly_2010-09-11_15:17:02  hourly_2010-09-12_09:17:02
hourly_2010-09-11_17:17:02  hourly_2010-09-12_10:17:01
hourly_2010-09-11_18:17:01  hourly_2010-09-12_11:17:01
hourly_2010-09-11_19:17:01  hourly_2010-09-12_12:17:02
hourly_2010-09-11_20:17:01  hourly_2010-09-12_13:17:01
hourly_2010-09-11_21:17:02  weekly_2010-09-02_07:51:13
hourly_2010-09-11_22:17:01  weekly_2010-09-09_16:00:25
hourly_2010-09-11_23:17:02  weekly_2010-09-12_07:52:39

Everything has been running fine for about a month. I haven’t filled up my disk with junk snapshots yet. One of the nice things about these writeable snapshots is that I can always prune big files that I don’t need right out of them.

It feels like it was a million years ago that I was just playing around with btrfs. I am not playing around any longer—my primary workstation (also known as my laptop) has been running btrfs as its root file system for a little over a month now.

I haven’t run any benchmarks, because I don’t want to know if it tests any slower than ext4. The machine feels pretty much exactly like it did before the switch, and that is good enough for me. The only thing btrfs has been absolutely terrible at is storing QEMU/KVM disk images. That’s a bit disappointing because copy-on-write snapshots and file clones of virtual machine disk images would be quite awesome, especially once deduplication hits btrfs.

How I Configured my Subvolumes

The first thing I did was store my / in its own subvolume. This makes changing your default root subvolume easier if you later decide you don’t have a need for the original again (if something like an apt-get dist-upgrade goes awry). It also lets you keep the real default btrfs subvolume unmounted and out of the way.

I ended up with five subvolumes:

• / – The operating system and config files
• /home – All my local user home directories; there is only one user
• ~/wip – My “work in progress” directory. Most anything I am working on. I broke this one out because it is the volume I am most likely to manually snapshot
• ~/tmp – Junk. Garbage. Mostly I untar and compile things here. This one gets its own subvolume because it is likely to fill up with junk that I won’t need. If I run low on space I can clobber old snapshots of this without even giving it much though.
• ~/Downloads – My default web browser download folder. Almost exactly like the ~/tmp directory.

This layout has mostly been working pretty well. I like that I can snapshot /home without accidentally storing copies of useless data in ~/tmp and ~/Downloads. I bet I have saved a few gigabytes by not snapshotting any Linux kernel compiles sitting in ~/tmp.

Unfortunately, I realized I would always like a snapshot of ~/wip with every snapshot of /home. It isn’t a big deal in practice because it is simple enough to script.

The Verdict

I’m very happy with btrfs. The performance is great for me in all but one use case. I’ve been wanting proper read/write copy on write snapshots on my workstation ever since the first time I read about zfs a few years ago. I’m so happy to finally have them!

I haven’t yet noticed any corruption (I hope!). However, I am running backups way more often than I ever did. I lost data to a file system corruption once (reiserfs on my dual Intel Celeron 366). While running ext3 and ext4 I was really only worried about hardware failure. Now I am worried about hardware and software failure, which makes me quite a bit more nervous.

There aren’t very many good Bluetooth mice on the market. One of my favorites is the Logitech V270. It is big enough to use but still small enough to be portable. It also sips on batteries and lasts for months on a pair of AA batteries. Unfortunately, it is absolutely useless for playing FPS games. It goes to sleep after a very short time period. It wakes up fast enough that you won’t notice it when you’re just clicking around on your desktop, but if you duck behind a corner to wait for an unsuspecting victim you will certainly notice the time it takes for the V270 to wake up…

Choosing a Mouse

There wasn’t a big selection of Bluetooth mice 3-4 years ago, and I don’t want to carry a dongle when my laptop already has Bluetooth. I ended up buying a used and discontinued Logitech MX900 on [eBay][15]. It is a fine mouse even if it is a little on the heavy side. Unfortunately it drains a pair of AA batteries in two or three days and lacks a power switch.

This wasn’t a big deal until I stopped using the laptop display and switched to a pair of external monitors. I used to just use the touchpad, now I have to use a mouse…

Why Do I Need the Dock?

The Bluetooth module in my current HP Pavillion dv8t laptop is rather underpowered. The signal is so bad that my mouse is very jittery when the laptop is it its hiding spot behind my desk (my old Dell Inspiron 6400 didn’t have this problem at all). The poor signal and the need for a battery charger were two good reasons to dig out the dock that came with the MX900.

I’m convinced that Logitech has absolutely no idea how to make a decent charging cradle. I was going through all sorts of contortions and dances trying to get the mouse to actually start charging when I placed (or slammed) the mouse into the cradle. I’m also lucky if it continues charging after I walk away. We have the same sort of problem with our older Logitech Harmony remote control; I might have to try this on him as well.

How Did I Fix It?

My fix was quick, easy, cheap, and quite ugly… I made two short cylinders out of aluminum foil that matched the diameter of the little charging contacts on the cradle. Then I just put them over the contacts and mashed them down in there. They may not look pretty, but they are small enough that they aren’t very noticeable. The mouse charges properly every single time I place it in the cradle now.

I have wanted to build an arcade cabinet for a very long time. I finally decided to stop thinking about doing it and actually do it!

Some of the Inspiration

I decided that we are going to build a four player cocktail cabinet. We like the design of the Crazy Canadian’s Custom Cocktail Cabinet. We might use nice-looking stain grade wood, but I really like the look of The NEON MAME cabinet with light blue t-molding on a black cabinet.

Some of our Constraints

I think a cocktail cabinet will be more useful than an upright cabinet, since it can also double as a table. I want this build to be more like a table instead of just a standard cocktail cabinet. I don’t want to have a box underneath, I want you to be able to pull a chair up to it and put your legs underneath. I also don’t want the control panels to stick out past the glass tabletop. I am also trying to keep the tabletop at about the usual height of a desk or table.

It turns out that this isn’t going to be as easy as I thought at first. The joysticks are fairly deep and you need enough room between the control panel and the glass so that you can comfortably use the controls. Our joysticks drop about 3 inches below the top of the control panel and we think we need about 6 inches of clearance between the panel and the glass. Fudging in one inch for the glass tabletop and the covering under the panel that will put the bottom of the controls 10 inches below the tabletop.

My desk is about 30 inches high. 10 inches below that would have the controls just about sitting on my chair. We’ve been figuring the tabletop height will end up having to be somewhere around 34 inches (maybe 33 if we’re lucky!). It is a little on the high side but shouldn’t be ridiculously tall.

Our life size whiteboard diagrams have the tabletop dimensions at about 37 by 29 inches using a 24 inch LCD panel. We’ve seen some deals on 36 inch square tabletop glass (for some reason square is significantly less expensive than a rectangle).

Control Panel Layout

We will definitely be using a 4-player layout. We thought about putting two players on one of the long sides of the cabinet. That would let me put the table up against a wall and it would be great for fighting games. We think it might be a little too crowded, though, so we will probably go with one player to a side.

What Games Do I Want to Support

The most important game this cabinet needs to support is Mortal Kombat II. I was in high school when Mortal Kombat and Mortal Kombat II were released and we used to play quite a bit.

The four-player game I have in mind is Gauntlet), though I’m sure there will be others. There is no reason to limit the cabinet to arcade games. I was thinking Liquid War would be a good fit.

The Parts We Have So Far

I ordered joysticks, buttons, and connectors from Groovy Game Gear. I was hoping to use their GP-Wiz40. It looks like a good product and a good value (and an even better value if you don’t mind soldering). Unfortunately, we need 44 inputs, and that is four too many.

I ended up going with an I-PAC 4 from Ultimarc. It has more than enough inputs and didn’t cost much more than a pair of GP-Wiz40 controllers.

I went with the HAPP™ Super Arcade Joystick. I am surprised how happy I am with them. They work very well as an 8-way joystick and they seem to make it pretty easy to perform circular-style moves in Mortal Kombat.

I also got buttons for players one through four and six HAPP Black Horizontal Pushbuttons for each player.

The Mock-Up Test Controller

We put some holes in a piece of wood and put together a test controller. It works great. The buttons feel right and the joystick feels great. We will definitely be going with the two-rows-of-three-buttons layout, but I am unsure what sort of spacing and staggering they will have. Yes, we indeed forgot to leave room for the Player 1 button…

The test controller has very arcade-like wide button spacing: 2.0 inches between button centers on the vertical, 1.625 inches on the horizontal. It seems a little too wide; I will probably tighten that up for the final product.

Plopping the control panel down on my desk isn’t ideal. Getting the half-circle moves to go off is a little hit or miss because the controller slides around. I don’t think it will be a problem on the real controls that are bolted to the table.

How Long is this Build Going to Take?

Hopefully not too long! We’ve been talking about this and drawing on the whiteboard for probably two months so far. Now that I have actually had a controller in my hands I am getting very excited.

I just upgraded to a (way too) shiny HP Pavilion dv8t laptop and a pair of inexpensive Sceptre 1080p LCD panels. The laptop seems to work pretty well with Linux. I'm running Ubuntu 9.10 with a 2.6.34-rc1 kernel, before the laptop got here I read that the latest kernels have better support for Turbo Boost. I don't know for sure if the kernel is helping me, but nearly every piece of hardware is working fine without any tweaking. So far I am unable to control bass/treble (the sub woofer makes it pretty loud this way), it does not report how fast the battery is being drained, and I'm unable to connect to my 802.11a access point.

These Sceptre LCD panels are WAY too red. I read warnings in the comments on Newegg before I bought them but I figured they couldn't be that bad. They are. Reds and oranges are quite bright. I've tried to tone them down and I'm not very happy with any of my results. I got exactly what I paid for.

What is All This Really About?

Enough about the new hardware! My goal was to be able to plug the laptop into the monitors and have everything just work without any manual intervention. If the two Sceptres are plugged in, I want the desktop to automatically expand across them and shut off the laptop display. When they're unplugged I want it to revert to the laptop display.

Using Two Monitors with an Nvidia Card

I started with the open source driver and xrandr. Using the VGA port was not a problem. For some reason, the open source driver was unable to detect when a device was plugged into the HDMI port. The proprietary Nvidia drivers did not have this problem. My hardware is able to drive any two out of the three displays. Unfortunately, it is not even able to use the third as a mirror of one of the other two.

Controlling the Outputs from the Command Line

I found an application called disper that makes it very easy to control the active outputs from the command line. First I used the nvidia-settings application to set up the two external displays the way I wanted them. Then I exported the settings with disper:

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disper --export > ~/.disper-sceptre

Then I used nvidia-settings to set up the single laptop display and ran:

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disper --export > ~/.disper-single

disper can list the displays that are connected:

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wonko@zaphod:~$ disper --list
display DFP-0: CMO
 resolutions: 320x175, 320x200, 360x200, 320x240, 400x300, 416x312, 512x384, 640x350, 576x432, 640x400, 680x384, 720x400, 640x480, 720x450, 640x512, 700x525, 800x512, 840x525, 800x600, 960x540, 832x624, 960x600, 896x672, 928x696, 960x720, 1024x768, 1152x864, 1360x768, 1280x960, 1440x900, 1280x1024, 1400x1050, 1600x1024, 1680x1050, 1920x1080
display CRT-0: Sceptre X226W-1920
 resolutions: 320x240, 400x300, 512x384, 680x384, 640x480, 720x450, 700x525, 840x525, 800x600, 960x540, 832x624, 960x600, 1024x768, 1152x864, 1360x768, 1280x960, 1440x900, 1280x1024, 1400x1050, 1680x1050, 1920x1080
display DFP-1: Sceptre X226W-1920
 resolutions: 320x175, 320x200, 360x200, 320x240, 400x300, 416x312, 512x384, 640x350, 576x432, 640x400, 680x384, 720x400, 640x480, 720x450, 640x512, 700x525, 800x512, 840x525, 800x600, 960x540, 832x624, 960x600, 896x672, 928x696, 960x720, 1024x768, 1152x864, 1360x768, 1280x960, 1440x900, 1280x1024, 1400x1050, 1600x1024, 1680x1050, 1920x1080

I wrote a short daemon-style shell script that periodically checks the connected displays and passes the correct settings to disper:

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#! /bin/bash
sleep 8  # The script crashes my X server if it ran too early

while [ 1 ]; do
  if [ `disper -l | grep -c X226W-1920` == 2 ]; then
    disper -i < ~/.disper-sceptre-dual
  else
    disper -i < ~/.disper-single
    sleep 2;
    xset dpms force on  # laptop display won't wake up without this
  fi
  sleep 10
done

I needed to add the xset dpms force on line or else my display would never wake up on its own. I don't know how specific that is to my hardware.

Xinerama and Xrandr

I don’t see any reason why this couldn't be adapted to work with Xinerama and xrandr. xrandr can easily be used to detect and configure the displays. I know xrandr sometimes caused the screens to briefly go blank on my old laptop when it was detecting displays. That would be a bit problematic…

I saw an article about Stealing from Padre for Vim and I got a bit jealous that this functionality wasn't already available for Emacs. I guess I lucked out because it was very easy to make use of App::EditorTools in Emacs.

It probably took about a half hour to an hour to get this all up and running. The hardest part was actually tracking down the elisp functions that would return the current row and column of the beginning and end of a region. The terminology was just not easy to search for.

I did not include any default bindings in the package. I am still not entirely sure where their permanent home will be within my own config. For now I am using these:

(define-key cperl-mode-map (kbd "C-c e r") 'editortools-vim-renamevariable)
(define-key cperl-mode-map (kbd "C-c e t") 'editortools-vim-introducetemporaryvariable)

I don't think I want a binding for the renamepackage/renamepackagefrompath functions. I think I might set it up to call one of those automatically when I create a new file.

The elisp file can be found at:

http://rcs.patshead.com/dists/editortools-vim-el/

A Darcs repository is also available at http://rcs.patshead.com.

I am a huge fan of whiteboards. I can never have enough. Early last year I started hanging some inexpensive 4’ by 8’ melamine panels in my new home office. One of the three walls wasn’t big enough for a full sheet. I had to cut that one to 4’ by 5’.

After over a year of use I am still very happy with all 84 square feet of melamine whiteboard. When I was first purchasing the melamine, I read a lot of complaints about how hard it can be to cleanly erase them, especially after the ink has been on there for an extended period.

I am using Expo Low Odor Dry Erase Markers. I've read that they can be more problematic, but that is the only kind that were on the shelf the day I was shopping for them. One of the colors didn't like to erase very well. We hung some of the left over whiteboard inside the door of our pantry. Any colors that ended up being difficult (or ugly, like brown) ended up in there.

Most of the colors that I use have erased pretty easily even after setting in for two months or more, but at that point they usually require a bit more effort. Unfortunately, today I had my first complete failure at erasing. The area I was trying to erase had been written on for almost a full year.

I don't have any special whiteboard cleaners here. First I reached for my little bottle of screen cleaner—my own mix of a small amount of glass cleaner in water. It worked just as well as the undiluted glass cleaner I tried next, which is not at all.

Fortunately, I remembered that I had a cheap generic Mr. Clean Magic Eraser in the closet. I sprayed the whiteboard with my screen cleaner, since it was handier than water, and scrubbed away. Everything came clean with barely any elbow grease. It was quite awesome!

I am apparently not the first person to think of this.

I did see some people who were wary of using these on whiteboards because they are a mild abrasive that might eventually wear down the writing surface. These melamine boards were very inexpensive. I wouldn’t mind replacing them every few years.

My Intel 80 GB X25-M G2 in my laptop died recently. Everything was running smoothly when I shut down, but when I powered back up the BIOS couldn't see the drive any longer. Fortunately, I keep pretty good backups, and I was up and running on a spare platter drive relatively quickly.

The RMA process was pretty disappointing. Phoning Intel was the only option.

I called in the afternoon on Monday, February 1, since they are only available during business hours. My time on hold was pretty short, probably about five minutes, and it took less than 10 minutes to get the RMA rolling. I was told I'd receive an email shortly with RMA instructions.

I didn't receive an email. At that point it was after business hours so I used their web-based form to submit a question. I included my RMA and case numbers, and I never heard back from them.

At this point there is a delay that is completely my fault. I didn't get a chance to call back until a week, later on Monday, February 8. It turned out they got my email address wrong. I pronounced my email address and I spelled it to them letter for letter. They didn't only have it wrong, they were short on characters…

I was happy with the turn around time on the package. I had the drive at the post office on Tuesday, February 9, and the new drive arrived at my door on Tuesday, February 16.

The night of my second call to Intel I realized there was a pretty good chance they also didn't get my address correct. They do not include your shipping address in the RMA email. This time I emailed the address listed in the RMA email, which is rma@mailbox.intel.com. I never heard anything back.

My Overall Opinion

I was happy with the service once I was able to get to the point where they were actually able to ship the drive out. I'm generally unhappy with their telephone support, and I am extremely disappointed with their email communications.

I Sure Did Miss the SSD

Certain tasks were noticeably slower. Most of the time the performance difference isn't something you can feel, but some disk intensive tasks are significantly faster with the SSD. Things like booting, installing and updating numerous packages with apt, and importing photos into F-Spot are at least twice as fast with the X25.

The thing I noticed most was the heat. When I first moved from the old hot platter drive to the X25 I didn't think the difference was so dramatic. Running on the SSD for months sure made the platter drive feel scary hot. The SSD is warm underneath the laptop where there is only a piece of plastic covering and physically touching the drive.

The platter drive even made the top of the laptop very warm to the touch. The difference in temperature is huge.

• Update: The replacement drive died in the middle or April 2010 (about 3 months later). It died in a different make/model laptop, my new HP DV8T, but under similar circumstances. The drive was fine when the laptop was cleanly shut down; the BIOS could no longer see the drive on next boot. The replacement-for-the-replacement has been running fine since then, it is now September 2010.