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Introducing North Coast Synthesis Ltd.

Wednesday 11 January 2017, 19:43

The synthesizer project has reached an important milestone: my business is now incorporated, under the name North Coast Synthesis Ltd. The Web site will be at northcoastsynthesis.com, which currently just redirects to a password-locked Shopify storefront, but will become public and have some real content in the near future. Watch this space, that site, or my Twitter account, for further updates as they happen.

A read-only root for Slackware ARM

Sunday 20 April 2014, 16:52

In my last posting I described getting Slackware ARM to boot headless on the ODROID U3 single-board computer, and I said that the next step would be to try to make it handle ungraceful shutdown (power loss) better. I plan to put this board into a Eurorack synthesizer module with no easy access to the microHDMI monitor connection, and SSH over the Ethernet connection as the only access to administrative functions. If, when the power is pulled on it, it comes up on next boot in a state where it requires console interaction to do a step like checking the filesystem before it will accept SSH connections, that is a disaster; I'd have to disassemble the whole module to extract the microSDMI card and replace the OS image. To be useful, the ODROID must be guaranteed or almost guaranteed to survive a power drop and come up SSH-able on the next boot. Ideally, I want pulling the plug on it with no shutdown formalities to be the normal expected way of shutting it down too, not just an error condition from which it can recover. A good journalling filesystem can increase the chance of recovery from occasional accidental power drops, but I think the only way to make routine non-accidental power drops safe is to keep the filesystem mounted read-only - which might be desirable anyway, to reduce wear on the flash memory and prevent its being corrupted by other kinds of accidents. So this posting is about my experiences configuring Slackware ARM on the ODROID U3 to keep its root filesystem read-only.

Slackware on the ODROID U3

Sunday 13 April 2014, 18:20

Our last episode concluded with the discovery that the clip leads I was using to power the ODROID U3 had nontrivial resistance, possibly close to two Ohms for the pair. That's a lot, when one is pulling up to 2A through them from a 5V supply. I switched them for some lower-resistance ones, and the ODROID seemed to behave much better. Between that and a replacement of the Hardkernel-supplied microSD card, I was hopeful that the reliability problems would be much reduced and I could make some progress on the software side of things.

More ODROID adventure, or "Young man, in this household we obey Ohm's Law"

Wednesday 9 April 2014, 20:39

As of last update, I had given up on setting up the ODROID U3 without connecting a monitor to it, and was shopping for a micro-HDMI cable. Here are some further notes

Some notes on the ODROID U3

Sunday 6 April 2014, 20:09

I recently bought a Hardkernel ODROID U3 single-board computer to use in one of my projects. The ODROID U3 is an ARM-based computer capable of running Linux or Android, with Ethernet, USB, microSD, and some other ports that I wasn't planning to use. My plan is to use it for controlling a music synthesizer, with the USB ports used to interface to the synth and a little LCD panel, and the Ethernet port used to talk to other computers. This posting contains some notes on getting it to work.


Wednesday 2 January 2013, 10:26

The title is a song lyric; it means "the story that starts now," and that's more or less where I feel I'm at. A lot has happened between mid-November and now, and I'm hoping that this will mark a boundary or change in the conditions around me.

LCD monitor adventures

Monday 23 July 2012, 16:16

I haven't had very good luck with computer hardware, nor operating systems, in the last few months. I lost a hard drive in my main desktop computer at home, and had to replace that (no data loss because it waS RAIDed); the latest Arch Linux "upgrade" made my computer unbootable because the maintainers decided they had to move everything from /lib into /usr/lib and the documented procedure for doing the upgrade safely didn't cover oddball configuration cases like having GCC installed (because who would have that?); and now my LCD monitor is dying.

More fun with technology

Friday 9 September 2011, 07:14

Looks like my home computer has stopped working. Most likely it's some kind of thermal-related hardware flakiness, and it'll be basically okay once rebooted. But since I am literally on the other side of the world from the machine in question, and it's not accepting network connections, there's not really anything that can be done about this situation until I return to Canada almost two weeks from now. Fortunately, I have enough other computing resources elsewhere on the Net that I can still do my email and Web log updates and the other things I really need to do during my trip; and all the data was backed up before I left, so even if the machine is dead in some more spectacular and permanent way, there'll be little if any really permanent damage. Some reference information that would be nice to have access to, is locked up on that computer and inaccessible with it not accepting network connections. Axel, sorry, but it looks unlikely that the astro charts will work until I'm back in Canada.

I sure don't seem to be having good luck with technology these last few days.

More updates

Saturday 18 December 2010, 13:24

Very soon I'll be taking down and packing my main desktop computer. Although I'll still be able to read and write plain text email and make Web log postings after that, I won't really have full connectivity again until early January. In particular, you should not expect me to be able to see anything sent as an attached file, such as photos or video clips. That means you, Mom.

eWaste follow-up

Wednesday 15 December 2010, 11:14

Left the dead computer and a cardboard box full of other electronic stuff out last night for collection early this morning, as directed by the building superintendent. It appeared not to have been picked up, and my guess was that notwithstanding what the superintendent said, we do not actually have garbage pickup on Tuesday nights, only on Thursdays. So I brought the items back in just now, thinking to leave them out again tomorrow night, Thursday. In so doing, I noticed that one item had vanished from the cardboard box: the dead motherboard from the Pentium III machine. The motherboard from the dual Celeron remains. It seems unlikely that the City would have pulled out just that one item to dispose of, so my guess on that is that either (A) I misremembered what had been in the box and it was never there to begin with (unlikely), or (B) some scavenger came along, looked carefully at the items, and decided that one was valuable enough to make off with. If so, they'll learn the hard way that it is kaput.

For great justice

Saturday 18 September 2010, 11:37

I'm not planning to post further continuous updates on my move to the new computer, but at least one correspondent commented that she hadn't seen any further updates in a while and hoped the new machine was working, so I thought I'd better wrap up some loose ends.

The new machine works. It will be a long time before I'm fully "settled in" on it, and a lot of software that used to work, doesn't work now because of the change. I will be fixing things as they come up, one at a time. But I've moved over my home directory, email is flowing in both directions, and a snapshot of the old machine at the time of the crash is now archived to DVDs, independent of my other backup measures. I'm basically back in business. A few loose ends and other comments, below.

We get signal?

Wednesday 15 September 2010, 15:40

So, here we are. It's 3:45pm on Wednesday, and I'm home again after a relatively brief trip to Waterloo. I wanted to be there this morning for a meet-n-greet meeting with some new students, but I found that (because of two and a half hours' sleep last night) I wasn't getting any work done, so I left shortly after noon.

As of 6:15am when I departed, the RAID build was in progress and estimated to finish in four hours, so about 10:15. It has certainly finished now. One other thing to report from the intervening time is that I managed to get through on the phone to the fellow from TigerDirect who had called me, and it turned out he wasn't phoning about the RAM RMA after all! It's just that they have some sort of AI that flags customers who look like they might be buying for a business, to get a personal call inviting them to use the company's B2B service. I wasn't a business and so he didn't have much to say to me. He listened politely to my description of the RAM troubles, but that clearly wasn't his department and he didn't and couldn't tell me anything I didn't already know about it.

So I shipped the RAM back to TigerDirect. I'd been holding off until I was able to talk to their representative, in case it was going to turn out that he'd tell me not to ship it back for some reason. It remains to be seen how much of it they'll reimburse.

Now, as the lady said to the tinker, let's have another round.

Main screen turn on

Tuesday 14 September 2010, 18:07

Tuesday, 6:05pm: Today I took time out from work for a trip out to Kennedy (the Eastern terminus of the main Toronto subway line) to visit Canada Computers (whose downtown store is out of commission, apparently because of a fire) and buy some G.SKILL memory to replace the Corsair memory that failed me. I was a little worried about this because the new modules are exactly the same spec as the old - DDR3 1333, CL9-9-9-24, 4x 2G modules, 1.5v. If the others didn't work, these shouldn't. However, the others said they were "for Intel" and these say "for Intel or AMD."

And they do work - at least as far as the computer will POST with two of them inserted. Next, I insert the others and make sure it still does; and then I start plugging in hard drives. My plan (since I have five drive bays, four drives I want to use long-term, and two drives to recover) is to start with three new drives; build a degraded RAID array (technically, several) with those; then attach the two old drives, recover their data to the array, remove the old drive and put in the remaining new one, and resync the array.

But first I pour a drink (sparkling water, I've run out of alcohol) and maybe think about some tacos, because it's going to be a long night. The next several updates will be additions to this entry rather than new entries.


Monday 13 September 2010, 13:50

I'm going to experiment with updating this entry in near-real-time as I work on putting together my new computer system. As of now (first posting) it's about 1:45pm. UPS, after claiming to have tried to deliver the package of parts at 10:23*, now says they will try again between 2 and 3. I plan to spend that hour waiting in the lobby to intercept the delivery person so there can be no excuse of "we tried to buzz you and you weren't there."

* I don't believe this claim because I was here at that time, they didn't buzz me, the buzzer is unlikely to be broken, and they didn't leave a "we missed you" card, as they would have if they'd actually gotten to the door and been unable to get farther. I suspect the driver took one look at the construction on Roncesvalles Avenue (which, granted, is scary), aborted the attempt, and told his** supervisors I hadn't answered. On the plus side, the customer service people I talked to subsequently were very polite and alleviated my anger a bit. The real test will be whether the delivery actually occurs, 15-75 minutes from now.

** Not a sexist assumption - I am talking about a specific individual known to be male; or at least, the customer service people told me they'd talked to "him" on the phone.

Or not

Thursday 9 September 2010, 23:01

Smoke test with new power supply, and opal's motherboard in diamond's case: no go. The fans spin up and then spin down immediately. On roughly one boot attempt in four, seemingly random iid, it gets as far as the single beep that is normal, and lasts a few seconds before shutting down. But nothing ever comes up on the video output. Same behaviour if I disconnect all the drives from the motherboard, except that (if left connected to the power supply) the drives by themselves will remain spinning. So it's pretty clear that the motherboard (or something attached to it so intimately as to effectively be part of it, such as the CPU or RAM modules) is fatally damaged.

Conclusion: This motherboard is dead. I have to buy a new computer. If I'm lucky, I'll be able to salvage the data from at least one of the hard drives. All the important stuff is on both, via RAID-1, so recovering one is enough to salvage that; and all the critically important stuff is off-site, so it wouldn't be an absolute disaster even if I lost both drives; but some low-priority (replaceable with annoyance) data is striped on RAID-0, so recovering it requires recovering both; and obviously it'd be nice to salvage as much as I can.


Thursday 9 September 2010, 20:59

Geekery below. This entry is in English notwithstanding the title, which is supposed to mean "from ashes, a new computer."

Curses, foiled again

Wednesday 8 September 2010, 22:50

I just came home to an unusual silence. No fans. My main desktop computer was not running. That's especially bad because it is supposed to come up all by itself in the event of a power outage. On further investigation, it seems to be in pretty bad shape. After a power cycle the fans and power light come on, and the drives sound like they're spinning up. The DVD tray ejects when the button is pressed. But there's no signal out of the VGA port, no response or LED flashes on the keyboard, nothing on the network. These are not good signs. It looks like something is really seriously wrong with this machine.

Between backups, RAID, and the other computer hardware I have around here, I'm sure I won't lose data and will be able to continue more or less carrying on my life. It's going to be rough if I can't get this machine or something very much like it up and running again soon, though. Any email that came in between when I last used it (around six pm) and whenever it crashed (could be as late as eleven) will be sitting on those hard disks until I get them hooked up to a machine that works. My main backup machine didn't work last time I tried to use it, and was slated to be decommissioned, so I don't know if I'll be able to use it to recover the main main machine. I'm writing this from the laptop, through the firewall (which is still fine).

And if, as looks to be the case, this machine is mostly or entirely a write-off, then I'm faced with the question of whether to get a new one now, or wait until after my move and have one less thing to move. I don't know if I can realistically run off the laptop alone all the time until then. At the very least I need to get a machine with a DVD burner up and running so I can back up the laptop's drive. I also wonder what I'll do with the scratchbuilt geodesic sphere case the apparently-dead machine is in, which I have never even quite finished building; unfortunately, if the electronic guts of the machine are dead then I think the sensible thing to do is write that off as well. It wouldn't be practical to to try put a new machine's insides into the sphere.

Time for a new audio/video player

Monday 7 June 2010, 12:01

The clicky spring inside the "forward" switch on my Visual Land VL-878 audio/video player has given up the ghost. As a result, it doesn't click when I press the button; instead, the button is activated by slight pressure and very easy to activate by accident. It is technically possible to still use the player with a lot of caution, but doing so is a lot less fun than it should be.