Microkernel Construction Lecture Notes: a detailed tour of the L4 microkernel, explaining the design decisions and performance constraints.

Jeanine and I wired up a power supply for three of the Shame Project lights this afternoon, while Ava mounted the light modules into three paper lanterns. We hung them from the ceiling in the corner over the couch. It’s a nice effect: a colorful, diffuse brightness, just enough to read by, with a slow, quiet color shift animation.

My sister Olivia got married this weekend. Her new husband Brian is a solid dude and I’m glad the two of them are going for the long haul.

Ava and I decided to drive down to Sacramento for the occasion, since flying basically just sucks anymore. I took Friday off and we cruised down I-5, arriving in Sacramento about ten minutes before the big post-rehearsal dinner at Spataro. We adjourned to the hotel bar, and stumbled upstairs at some very late hour.

Saturday we wandered down K Street, hung over, and did a little shopping. Then the wedding: a small church, full of guests, strewn with leaves. The tone was very serious, until the end: my mother hired a local high school marching band to do the ‘Love Actually’ musical surprise, with a big thumping snare drum and a tuba. It was fun, if a little chaotic. We all took a stretch Hummer back to the hotel for the reception.

Sunday we kidnapped my sister Jeanine, dropped the convertible top, and set off northward. It was sunny and pleasant until about ten miles from the Oregon border, when it got cold. The California / Oregon border may be a mapmaker’s straight-line fancy, but there is a genuine ecological boundary there too.

Jeanine is between jobs and rounds of schooling at the moment, so she’s going to hang out with us for a while and explore Seattle. It’s all rather ad hoc – we have no idea how long she’s going to stay or how she’ll be getting back to Sacramento when she goes. But, whatever, it’s fun to have her around!

All of Fremont lost power this afternoon. There’s a distinctive groan you hear when an office full of techies all find their computers dying at once: frustration, with an undertone of amusement – because it’s all backed up, really, and if the power doesn’t come back quickly enough, we’ll just all take the rest of the day off.

So here I am at home, thinking about what I can do with three unexpectedly free hours this afternoon…

I should mention the fact that I have knocked another item off my project list: I had to stay up late last night, and there was some 20 minutes of tweaking to do before I went to work, but the mysterious music project is finished.

I just finished signing the new ALTSpace lease. This is it, we’re actually expanding! Now we just need to work hard at recruiting more people to help us pay for it all.

I did some more work on the mysterious music project last night. 60 bars completed out of 88 planned, and the next 16 bars are half done. I have gotten through the hardest part now: a section of six-voice polyphony, in counterpoint. I’ve never composed anything quite that tricky before. I’m hoping to finish the rest tomorrow night.

How to program an ATtiny45 or ATtiny85 microcontroller using the Arduino software and hardware. Includes add-ins for treating these microcontrollers as a different kind of Arduino board. The ATtiny chips are tiny and cheap; if you can solve your problem using no more than 5 I/O pins, they cost about $2 in single units and closer to $1.25 in quantity.

Fluid Nexus is another distributed, peer-to-peer messaging technology. This one is implemented as a smartphone app, and uses multiple communication protocols as available:

Fluid Nexus works on an opportunistic, broadcast model whereby it searches for any other device in its vicinity via network modalities that must be explicitly enabled by the user: Bluetooth, and link-local connections over WiFi via zeroconf service discovery. No messages are sent if you are only connected to the Internet via 3G/EDGE.

I’ve just finished the last details on the light dimmer box I’ve been building for Hunter Cross. He’s constructing a large “geode” sculpture which is supposed to glow, and he wants the lights to pulse like a MacBook sleep light. The project has gone through a number of major design changes, so the device I’ve ended up building is rather less elegant than it might have been had I designed it to do this job from the start, but it certainly does the job it needs to do. That is, it supplies up to 30 amps at 12V DC, running a 500 Hz PWM duty cycle, and modulates the pulse ratio with a perceptually linearized sine wave.

It looks pretty.

The background light in this video doesn’t actually change; that’s just the camera compensating for the additional brightness as the light on the desk fades up.

Crashed my bike tonight. I am still confused about what exactly I did wrong, but one minute I was riding along 23rd Avenue, and the next my bike was slipping out from under me, and then I went rolling down the street. There was a paint stripe across the street at about the right place, so I think I must have lost traction going across it, but I really don’t know what happened.

I had all my leather on and I am really glad I did. My ankle is sore – I must have twisted it as I landed – but I got right up and moved my bike out of traffic. I have no scrapes or significant pain, basically just bounced off the pavement. My left hip is a bit sore but not in any serious way.

The bike suffered more damage than I did, but it came off pretty well too. The headlight is crooked, the handlebar is torqued funny, the mirrors went every which way, the turn signal broke, and there’s a dent in the gas tank, but the engine guards did their job and the road rash on the tip of the exhaust is not visibly any worse than it had been before. It’ll all clean up except the dent in the gas tank, which I’m pretty unhappy about.

Well damn – I was really happy about the way I had been not crashing this bike. I laid each of my previous three bikes down within two weeks of buying them, so I’ve actually been doing pretty well with this one.

That didn’t take long: one month after Burning Man, I’ve built up a long enough list of active projects that I’m starting to feel overcommitted. Currently occupying parts of my brain:

0) Electric skateboard (designing tilt-steering mechanism)
1) Full-spectrum, 13000-lumen LED array contra Seattle winter darkness (awaiting parts)
2) ALTSpace expansion, up to 2600 square feet (paperwork, cat-herding)
3) Living room couch back piece (awaiting material)
4) Mysterious music project (20 bars finished out of 88 planned)
5) Proposal for City Light public art project (idea imagined, need to write it up)
6) Electrical engineering work on Hunter Cross’ “Geode” project (an evening’s worth of assembly to do)
7) Radian (ongoing! just finished a speedy new X64 code generator backend)
8) Repackaging some of the Shame Project lights for use in my living room (awaiting parts)
9) Small new custom serger workbench at ALTSpace (acquired parts, need to do carpentry)
10) Rhythm music synthesizer algorithm (thinking about it, doing no actual development work)
11) Powdercoating most of the chrome parts on my bike (next up: luggage rack / back rest)

Recently finished:
– Repaired the door frame and installed a new door at ALTSpace
– Built a storage shelf under the big work table at ALTSpace: storage for 12 more bins
– Powdercoated my bike’s headlight bucket and replaced the dented headlight retainer ring

I don’t actually have any clothing projects under way right now; it’s all electrical stuff and software. I have ideas and material purchased for half a dozen new garments, but they are pretty far down the priority list right now so I am not actively thinking about them. Also, my Pfaff is still broken; I need to get the timing adjusted again.

Oh, yeah! I have a day job, too! I work at Google. Right.

Way back in June, Ava and I started building an L-shaped couch for our living room. We built the frame, glued on a layer of memory foam, wrapped the whole thing in cotton batting, started sewing the upholstery, and then – ran out of fabric. Since it was some fancy stuff we’d ordered on eBay, we couldn’t just run out and buy more… and by the time the new order arrived, the summer art project season had gotten under way and the couch project landed on the back burner.

Yesterday we both had a day free, so we decided it was time to get this piece of furniture done. We finished cutting out the upholstery pieces, then I got to work sewing them together while Ava turned a piece of plywood into an elliptical, notched backboard and covered it in foam. Once the upholstery was done we wrapped the bench and stapled the fabric down – hundreds of staples, very sore wrists.

We ran out of steam before finishing the back piece, but the chair is done enough to sit on now, and it looks as nice as we’d hoped it would. Ava picked out the fabric, and while I raised an eyebrow at the idea of buying $35/yard upholstery fabric sight-unseen over the Internet, I’m really glad she stuck with the idea because the result looks great.

Seattle City Light wants to install some art projects at two of their facilities:

The Seattle Office of Arts & Cultural Affairs, in partnership with Seattle City Light, seeks two artists to create semi-permanent, site-specific installations for City Light’s North and South Service Centers, hubs for City Light’s work. Each selected artist will create up to two artworks that may be two- or three-dimensional to hang on walls. The artworks should capture the “electricity” of City Light’s activities.

Right, well, I’ve never been particularly interested in getting permission to make things, and interacting with a public agency seems really strange and awkward, but this also seems like exactly the right environment for the kind of algorithmic animated light sculpture project I like to build. I mean, it’s the power company, and their name is “City Light” – whether they know it or not, they really, really want something that incorporates a whole lot of LEDs. They have budget, too: $23,500 for each building. That’s enough to do something really very cool indeed.

The first thing that comes to mind echoes a piece I saw in the San Jose airport: thousands of panes of LCD shutter glass, switching between transparent and translucent states. It’s a subtle thing; it is animated and lively, but it doesn’t reach out and grab you with the force of its brightness. Instead you just get this constant motion and shimmering reflectivity.

It strikes me that a power company is fundamentally all about intervening in natural processes. It’s all driven by the Sun, of course; we capture energy directly from the sun using photovoltaic cells, but primarily we capture energy from the hydrological cycle using dams, and energy from temperature differentials using wind turbines. And fossil fuels are of course nothing but chemical storage for millions of years of ancient sunlight… The point of a power company is to extract a uniform, controllable source of energy from the wild, chaotic environment around us.

So I’m imagining an art piece which puts that wild, chaotic environment in a bottle. An array of glass jars, all shapes and sizes, all clear, frosted inside, hanging from the ceiling, in a hexagonal grid, at varying heights. Each one has a light – a high-power LED, of course – and together they render the output of an evolving wave algorithm. The algorithm would of course be the one I developed for the Cuttlefish project, oh so many years ago… but monochrome, I think. Just light. Or perhaps a very subtle, muted tint, even more muted than what I did with the Shame Project lights. It’d look like waves, like clouds, like the wind running across the grass; it would ripple and sway and move, and it would never, ever repeat itself.

ALTSpace has been operating at close to peak capacity all summer, hosting a lot of work for the Shame Project and the Groovik’s Cube as well as many smaller projects. We’ve decided to expand into the unit next door, doubling our floor space: the current tenants will be out at the end of the month, and there’s a door we can unlock on the common wall which will connect the two units, so we will have one big happy 2400-square-foot makerspace.

We will be able to set up more work tables and more storage lockers, which means we can bring in more members. We will also have room to expand our machine shop to triple or quadruple its current size – a partition wall and a new drop ceiling should give us enough soundproofing to run power tools. If all goes well we will be able to move in a mill, a lathe, and a 2D CNC router table! Very exciting – this will greatly expand the range of projects it will be possible to build there.

Sometimes a new project idea grips my brain with sudden, sticky determination. I came back from Burning Man thinking almost nonstop about a couple of small electric vehicles I’d like to build for next year. The first is a jumbo-size electric skateboard. I brought a normal electric skateboard to the playa in 2007, but the playa beat it hard, and after only a couple of rides the suspension was destroyed. It was also geared too high for the dusty, rutted condition of BRC roads after the first day or two. Of course you can buy larger, burlier “off road” skateboards, but they get expensive very quickly, and don’t have the kind of range I’d want at Burning Man. So I bought a four-wheeled electric mobility scooter at a garage sale ($150!) and took off all the bodywork. It has a 1-HP, 3400 RPM motor with differential, four pneumatic tires, a steering linkage, and two 12V batteries – perfect! Next I’ll replace the motor controller with something more appropriate for a skateboard, then add a deck and set it up for tilt steering. Add on some obnoxious LEDs and it’ll be done.

The next vehicle I have in mind is something like the Atomic Zombie Streetfox: a recumbent-style reverse trike, with two steering wheels in front and a drive wheel in the back. I plan to build it out of mountain bike components, so each wheel will be independently suspended, and an array of deep-cycle batteries under the driver’s knees should power it up to about 20-25 mph. That’s fast enough I could conceivably use it to ride to work and back – and Google already has electric-vehicle charging stations in the parking garage…

Oh well, who knows if I’ll actually finish it all, but it’s certainly interesting to think about. I’ve been learning about Ackermann angles and freewheels and high-current PWM driver MOSFETs…

This is a key reason I keep coming back to Burning Man:
Burning Man is for amateurs.

It’s Burning Man’s rank amateur status that keeps it alive and interesting and challenging to the culture at large in a way that raves never were and TV can only dream of. After all, the mechanism of appropriation is to bring professionals in and have them do things to spec. Amateurs are unpredictable. They’re in it for the passion, not the money, and they’ll follow their passion way past spec: amateurs can’t be co-opted as long as they stay amateurs. Burning Man can’t be co-opted as long as amateurs are the one’s really driving the culture.

And they are: Burning Man’s “no spectators” ethos turns everyone at the event into an amateur impresario. If you can’t sit back and watch then you have to do something, and if you’re not getting paid for it you might as well do something you’re passionate about.

I’m back. I’m alive. It was a great burn, probably the best one I’ve had. The project worked well, the group functioned smoothly and without drama, the weather was perfect (no whiteouts!). There were lots of interesting art pieces to look at, and I’ve come home with a couple of new projects rattling around in my head…

I’m wiped out today, after driving down to Bend and back yesterday to pick up the BMW. Its water pump seized on the way home, so we had it towed and then drove home in a rental Mustang. The trip was about 660 miles; I’ve driven more than that in a day before, but for some reason today I’m just exhausted.

Between work and Burning Man, I’ve been very busy lately.

This article from the Guardian is a remarkably sensible, thorough look at hackers, hacking, and most especially hackerspaces.

Today marks the end of week two at Google’s office in Seattle. So far so good: I’m still busy trying to figure out how things work, and haven’t actually written any code yet, but that seems to be normal and nobody expects otherwise. The project is reasonably interesting, and work practices require a reasonably low level of overhead.

Preparation for Burning Man now occupies all of my free time. I was hard at work on a custom tent, designed for better playa comfort than a standard camping tent, until I somehow managed to misalign the timing on my industrial sewing machine. I didn’t know that sewing machines had such a thing as timing, and I have no idea what I did to cause this problem, but the big green beast won’t make stitches anymore. I took it down to C. H. Holderby this morning for service, but they don’t expect to have it back to me til Tuesday, and that’s too late to get the project done before the trucks leave. Oh, well, I guess I’ll be enduring another crappy tent experience this year after all.

The Shame Project light hardware is done. We had a last work party this week and built all the wiring harnesses that will power the lights. After a 48-hour soak test, the lights are still burning bright and the power supplies are barely warm, so that counts as success. The software is not quite done, but the boards are designed for in-field reprogramming, so I can actually keep working on the code until the last minute if necessary. The big issue is that I haven’t gotten the network going yet. Each board has two serial ports, so I can connect all the lights in a daisy-chain; my plan was to use the hardware UART for one of the ports and a bitbanged software implementation for the other. I’m using the NewSoftSerial library for the software port, but I haven’t yet gotten it working correctly; it will receive data, but seems to lock up after transmitting. Oh, well, more debugging this weekend.

I should really get a bike, pick out a wardrobe, and pack up my gear pretty soon, but it’s been tough to feel motivated. I’m not actually excited about the playa experience this year; I’m going because of the Shame Project and not so much because I want to go hang out in the desert. It’s too easy to think of the heat and the dust and the general nuisance of it all. But I’m excited about the art project: this is the biggest canvas I’ve ever had to paint on. Yes, the groovik’s cube was bigger and more visible, but my contribution was purely technical. With the Shame Project, I get to present an evolving lightscape of my own imagination, projected across the skin of what counts as a very large building in playa terms. It’s a great opportunity and I am excited to see it all in action.

Google orientation week has gone well. There are three more lecture sessions on my calendar today, then I’ll go pretty much straight home. I had originally planned to stay Friday night and go back Saturday, but there’s not much to do in Mountain View, and I’m eager to get back home to Ava.

I suppose the real test will come when I show up at my Seattle desk and start figuring out what I’m actually going to be doing, but so far I feel like the orientation curriculum has done a good job of ramping everyone up at a steady, manageable pace. I’d probably enjoy myself more if things moved more quickly, but it’s better than being overwhelmed right up front. We’ve had overviews of the dev tools and the whole data-center architecture, an explanation of the search system, and practical exercises with the custom source-control and build tools. There is a lot of learning ahead, of course, but at least now I know what the general layout is and where to start looking for things.

Google really seems determined to take care of its engineers. It sounds almost too good to be true, but they’re walking the talk.

I have survived my first day at Google. I have a badge and a laptop and no idea how to actually do any coding. I expect that some training session during the remaining four days of orientation week will touch on that topic.

The Central District News published an article about ALTSpace, with pictures. Whee! We come off sounding pretty cool, even.

Sunday project: I built that evaporative cooler in a bucket I was talking about earlier. The original was intended to run on 12V power, but our camp is going to have a generator, so I substituted an AC fountain pump and a bathroom exhaust fan for the harder-to-find 12V units they picked out. The local home depot does not stock swamp cooler pads (“DuraCool”), so I made do with a cut-to-fit furnace filter.

Seems to work OK, though the air here is not dry enough for the cooling effect to show up that much. Still, it was about an hour’s labor and $70 worth of parts, so it’s at least a worthwhile experiment.

Friday project: I cut apart the cover for the Corbin seat that came with my Nighthawk, used the pieces as a pattern, and remade the whole thing out of leather. Then I stretched the new cover over the old foam and glued it down with contact cement. It was about six hours of work altogether, and the glue stank up the workshop something fierce, but the result looks pretty good. It feels good to ride on, too.

Hello there. It took a few days to really recover from that backpacking trip, and I’ve had a lot to do in the meantime.

The hike was about nine days, covering 85 miles and four mountain passes. It was the most intense hiking I’ve ever done: and yet it was only a third of the whole hike my younger sister Jeanine is doing. She’ll finish up on August 2nd by climbing Mt. Whitney, a 14,500 foot peak which is the tallest in California (and all of the lower 48).

We started at Red’s Meadow, a campground near Devil’s Postpile. First day was fairly nondescript; we basically just had to climb back out of the lowland and gain some elevation on the way to the first pass. It was harder for me than her, since I was not acclimated to the altitude or accustomed to the mileage, but I kept on chugging and we made it to our intended camp site.

The next few days were really nice. We camped near high alpine lakes, climbed snow-covered passes, tramped through meadows full of wildflowers, trekked along ridges, forded rivers, and generally had a great time. We got into a rhythm and generally arrived at our campsites an hour or two ahead of schedule, despite never making any particular haste to leave camp in the morning.

Eventually we reached Muir Trail Ranch, where our resupply bucket was located. Resupply went fine but things got a bit more difficult after that. We tried to find the prominently-advertised hot springs across the river, but it turned out to require a mile of bushwhacking and a highly dicey log scramble across a deep, narrow river gorge. When we eventually found the hot springs they were small, muddy, and full of algae… not exactly inspiring. Oh, well, we made do and had a good evening regardless.

The next three days were much more challenging. We got off to a slower start as we had to work our way back out of the bush to the trail, and then we had a long hot unshaded hike along the San Joaquin River valley and then up into the Evolution Valley turn-off. It was not a bad day but it was a very long one and we spent most of it climbing.

The next day was the real killer. We climbed up to Evolution Lake, which was gorgeous, but quickly became mired in a slushy, hazardous, seemingly endless snowfield. The sun was hot and there was no breeze; we toiled up the unstable slope for hour after hour, never able to settle into a steady, efficient hiking rhythm. We finally reached the top of the 12,000 foot pass at 4 pm, having originally intended to lunch there, and spent a while just laying around recovering.

Our schedule completely blown, we decided to have dinner, rally our strength, and go just far enough down the other side to camp at the first reasonable spot. This would make the following day harder but we were bushed and the thought of pushing on another five miles was unbearable.

Our spirits rose as we crunched down the equally squishy far side; at least we didn’t have to keep hauling ourselves up this mess. We eventually found a good spot at what we called “Frog Lake” due to all the frogs hopping in and out along the shoreline.

This happened to be my birthday, so I pulled out a flask of bourbon I’d packed for the occasion and Jeanine whipped up a special dessert she’d been carrying. We were so happy and relieved to have made it through the pass that we didn’t care about being tired and sore and wet and miles behind schedule.

Next day, then, was another long, hot climb. We made up our extra miles by 11 am, then started climbing up to the Dusy Basin area. It was another mostly shadeless climb back up to 12,000 feet, and we were plenty footsore by the time we arrived, but there were lots of gorgeous mountains and meadows and cascades to look at.

This was nearly the end of the line for me: in Dusy Basin the resupply crew met us. Mike and Joel continued on with Jeanine, and I hiked back out over the Bishop pass with Brian. I was eager to be done by this point so we trekked straight on til the parking lot, not even stopping for lunch. Of course we hit the first pizza place we saw in town.

It was great. I’m glad I did it. I’m impressed with Jeanine’s ambition and really glad I could help her achieve her dream. It’ll be a long time before I have another chance to take a backpacking trip this intense, and I’m sure I’ll remember this one fondly for years to come.

Back at my mom’s place in Sacramento after nine days of backpacking.

Longest, hardest trail I’ve ever walked.

More later.

Back from four days in Yosemite: that was fun! It was a big family-reunion trip, nineteen people total. We started at the Mono Meadow trailhead, off the Glacier Point road, and hiked down to Illilouette Creek for the first night. Scattered along the sand bar, our tents didn’t so much look like a single encampment as a whole miniature campground.

The water is unusually high this season, especially for July, as California had the same late-blooming summer we did in the Northwest. The creek was roaring away with surprising force, and the normal ford was completely unusable. We scouted up and down a bit and found no good options; there’s a great log bridge a couple hundred feet downstream, but it sits right above a very turbulent rapid and the spray from the high water made it slick and dangerous.

Solution? Engineering! Among nineteen people we had a good supply of burly dudes with upper body strength, and so we set about constructing a log bridge. We found a spot where the current split around a little island, located a couple of downed trees small enough to move, and started dragging the rocks and logs around. After a couple hours of hard work in the sun, we had built a rock pier on either side, and used ropes and levers to stretch two small logs across.

This was the point where a park ranger ambled up and casually inquired about our project, and just as casually let us know that there was, in fact, a decent fording spot upstream, just around the bend where we’d called off our survey expedition, and mentioned how he’d just guided three fairly short and not particularly burly women across it with no problems…

So we abandoned our mostly-finished bridge, trooped upstream, took off our boots and waded across. It was quite a production, but it worked and it was definitely less labor-intensive than the bridge.

Right, then: we trooped along through some open country full of blackened tree stumps, with little creeks and springs and wildflowers along the way. Above us, the domes of Mount Starr King; across the way, views of Glacier Point and Half Dome. We intersected the Panorama Trail, then tramped down the Nevada Falls trail, across the bridge, and on up to Little Yosemite Valley.

The campground there is so well developed it hardly feels like backcountry at all. It has designated camp sites, fire rings, bear lockers, and even toilets; only the fact that there are no cars distinguishes it from any of the valley campgrounds.

The next day was our Half Dome climb. Mom convinced us all to pack up our daypacks the night before, so we actually got our caravan out on the trail by 9 AM. It’s not a long hike – only three and a half miles – but it’s all elevation, so it’s not particularly quick going.

What’s to say about Half Dome? It’s an unusual mountain climb, with very clearly defined stages as the geology changes. First you walk up through the forest for a couple of miles, past the trail junction. Then you wind your way up the side of the ridge to the tree line. Then you walk along the ridge, with bare scrubby trees and increasingly dramatic vistas, to the lunch spot at the base of the sub-dome. Then it’s up a rugged, sun-exposed granite switchback stairstep section to the top of the sub-dome. A little bit down to the saddle, and the views are wider and the exposure more terrifying – then you climb the cables.

Our trip up the cables was more like a traffic jam than a normal climb; we were stuck with some genuine slowpokes ahead of us, who not only spent minutes at a time resting between each set of poles, but had themselves clipped in to both cables so that it was impossible to pass them without climbing outside the cable route. It was an exercise in patience: hanging on to the side of a mountain, just standing there, waiting for someone up above who seemed to be taking their time for no particular reason, while dozens of people just waited.

Oh, well. We all made it to the top, and we spent an hour wandering around looking at things and taking lots of group pictures. The trip down was also somewhat slow but not as bad as the trip up, and then it was just a long steady downhill hike back to camp, where we all grabbed our swim gear and went straight for the river.

We spent that evening celebrating Joel’s birthday around the campfire. There were miniature blueberry cheesecakes for all, a rhyming blues jam with rhythmic accompaniment (bear cans make great hand drums), and general foolery and merriment until late.

The trek down from Little Yosemite Valley to (big) Yosemite Valley is always an interesting social experience. You follow the line of the Merced as it drops first over Nevada Fall and then Vernal Fall; the latter is one of the most-visited attractions in the park, so the trail gets increasingly crowded the further you go. By the time you’ve descended the Mist Trail – a veritable shower this year, clouds of spray drenching us as we walked – you’ve left the back country and entered the land of poorly-shod, inexperienced day-hikers who stare at your towering pack like you’ve just come back from the Moon.

Our first destination was of course the pizza deck at Curry Village where we tore through seven large pizzas and a dozen or two glasses of beer, then headed for the showers and demolished a stack of clean towels. Oh yeah.

It’s a beautiful place. I love Yosemite. Things have changed, though; the Valley was crowded and full of cars. We spent literally hours sitting in stop-and-go traffic jams just entering and leaving, and ended up missing the Glacier Point bus due to the unexpected congestion. I missed the sense of calm welcome I’ve always had in Yosemite before. It’s been thirtyish years now, and things have changed; I’m not sure I want to go back to the Valley now.

Process isolation rediscovered as a programming pattern: an argument for the idea that fork/exit style process management is a useful model for software development within processes and not just between them.

Just learned about a place called Mars Restaurant, in the U-district. I don’t care what the place is like – I have to go there and check it out.

Here’s an article demonstrating how to build your own swamp cooler, capable of dropping air temperature by 20-30 degrees, out of ordinary hardware store parts.