Red Echo

April 30, 2009

loop machine version 2

I’ve built the box and the support frame for the electribes and the mixer. now I wait for the glue to dry… then build brackets for the repeater and the fx units.

April 27, 2009


Another offering in the imminent market for general-purpose electric motorcycles is the Mission One. They are going way upmarket, though, with an estimated retail around $70k. Cool as the styling and 120-mile range may be, they’re pretty firmly stuck in a niche with this one.

April 26, 2009


April 24, 2009

I haven’t done any work on Radian since late February. I’d like to get back into it, but it’s going to take a while to remember what I was doing and why. I was in the middle of a module which builds three-address intermediate code from a flowgraph, inverting the functional description into a list of imperative instructions…

April 23, 2009

An even more interesting electric motorcycle option is the Electric Motorsport GPR-S: specs are comparable to the ZeroX bike, but it’s a little faster (up to 70 mph), a fair bit cheaper ($8500), and styled like a street bike rather than a supermoto. It is also available now – they are reported to have shipped actual production bikes to actual customers.

April 21, 2009

Interesting discussion of some difficulties in designing a compiler for the Ruby language.

April 20, 2009

electric motorcycles

This is a hub motor for gas-to-electric motorcycle conversions. The motor is built into the wheel, so there is no mechanical linkage; you just scrap the entire drivetrain and replace the rear wheel. Selecting and installing batteries is an exercise left for the reader, but this design removes a significant challenge from the conversion process.

It’s a small outfit – two brothers commercializing their hobby, from the look of it – but if they outsource the manufacturing there’s no reason they can’t produce a quality product at a reasonable price. It’s just a start, but it’s great to see this kind of thing becoming more practical.

Performance, of course, totally sucks – the EnerTrac specs suggest a top speed of “60+” – but the hub-motor design suggests that a hybrid bike might be practical. I can imagine adding a sprocket to one of these hub motors and installing it on a standard bike, then simply cruising around on battery power whenever low speeds and stoplights are involved. Using the electric motor for acceleration and the gas motor for cruising would save energy overall, without sacrificing speed, acceleration, or range. Assuming you’d purchase an off-the-shelf motor controller, the chief design problem would be the composition and location of the battery pack.

addendum: someone in Colorado has converted their FJ600 to electric power, using a more conventional chain drive setup. Top speed is 66 mph, using a 72-volt battery, but range is only 18 miles – nickel-cadmium is lightweight, but energy density sucks.

second addendum: Zero Motorcycles has announced an all-electric street bike, claiming availability next month at $10k. Specs are 60 mile range, 4-hour charge, 31-hp motor, 60 mph top speed. It may top out quickly but it’ll feel like a rocket getting there – that motor puts out 62.5 ft-lbs of torque, and the bike only weighs 220 lbs, so it will accelerate like nobody’s business. Fun, fast, reasonable commuter/errand-running range, no assembly required: $10k is high, but that’s to be expected for the first generation. The electric motorcycle era is much closer than I realized.

April 19, 2009

Deception Pass loop

I went riding today, with Adam, Hilary, Divide, and Gary. MJ took my pillion seat. We met up early in the afternoon, cruised up I-5 and over to the Mukilteo ferry, then rode the length of Whidbey Island. The day started out overcast, but cleared as we rode; by the time we rolled down the windy little road to the north beach at Deception Pass State Park, it was a bright, blue, beautiful day. We skipped rocks and watched the boats cruise back and forth… then continued the loop across to Mount Vernon and straight home down I-5. Even factoring in a few minor technical problems, a seagull attack, and a massive traffic jam, it was a thoroughly enjoyable day.

April 18, 2009

I am sorry to say that Ava and I did not get married today. I broke off the engagement on Wednesday. The stress of planning the wedding and preparing for the next step in our lives strained our relationship too much to continue.

I have nothing but love, respect, and hope for Ava.

April 11, 2009

bachelor party at Garage

April 6, 2009

moto season continues or begins, depending on weather tolerance

The sunny weather this weekend brought all the motorcyclists back out of hibernation. It’s finally warm enough to skip the sweater I’ve been wearing under my jacket all winter, and my bike no longer needs a push when I start it in the morning. When I got to work today, the motorcycle zone in the parking garage was completely full. I’ve been parking there almost every work day for the last year, and that’s never happened before. I actually had to do a loop around the garage looking for a spot – there were bikes stashed everywhere.

Yesterday afternoon I cruised over to the Rocket Factory after dropping Ava off at her aerials class and spent an hour doing some basic tune-up work. I changed out the plugs, put in some new oil, and topped up the air in the tires. The back tire is new, replaced a couple of months ago, but now it looks like the front tire is reaching the end of its life as well. I’ve put a lot of miles on this machine – I don’t have an exact count anymore, but twenty miles every work day adds up fast.

April 3, 2009

On the topic of marriage: I am getting hitched, and soon. Ava and I will be exchanging vows, rings, and kisses at a little ceremony on the 18th, with a great big party to follow. It’s scary, of course, but exciting; this is clearly the right way for us to go, and I am looking forward to our future together.

The Iowa Supreme Court has just unanimously invalidated the state’s same-sex marriage ban. Iowa! I had no idea such a case was even in the works there. Now we must hope this doesn’t provoke a Proposition-8 style backlash – though California’s Proposition 8 has brought on a backlash of its own, with a Supreme Court challenge, a counter-petition, and proposal to remove all references to marriage from California law, substituting “domestic partnership”.

April 2, 2009

The Transactional Memory / Garbage Collection Analogy:

The purpose of this article is not to rehash excellent but previously published examples where software transactions provide an enormous benefit (though for background they are briefly discussed), nor is it to add some more examples to the litany. Rather, it is to present a more general perspective that I have developed over the last two years. This perspective is summarized in a one-sentence analogy:
Transactional memory is to
shared-memory concurrency
garbage collection is to
memory management.

The prose style is excessively wordy for my taste, but the content is interesting, and the core idea is entirely compatible with my own opinions on the subject.

April 1, 2009

I’ve never used Gmail. I’ve always had my own domain with its own mail server, and until I came to Microsoft I worked at home, so I only read mail on one computer anyway. The web-mail idea has started to make more sense now that I have a conventional commuter lifestyle, but I’m still not comfortable letting the Googlebot read my mail.

It occurred to me this afternoon, however, that the Googlebot already does read most of my mail. I just had a look through my 250 most recent messages, and after filtering out web site notifications (facebook, amazon, paypal, etc), 80% of the messages were to or from gmail users.

I am not entirely comfortable with this fact, but I can’t think of anything anyone could do about it.