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Comment: Re:Question... -- ? (Score 1) 215

by Ed Avis (#47348819) Attached to: Exploiting Wildcards On Linux/Unix
Yes, there is a workaround you can use, if you know about it and remember it every time, to enable the safe behaviour. That does *not* count as 'problem solved'. To solve the problem, the safe behaviour needs to be the default, with the funky and unsafe behaviour of treating filenames as extra switches being the one you have to enable specially. Really - what are the odds that the user or programmer *intends* for a file called --foo to be treated as an option specifier when they expand a wildcard? Conceptually the fix is not hard. Each element in argv gets an associated flag saying whether it is a filename - and if it is marked as a filename, getopt() or whatever does not treat it as an option specifier even if it begins with the - character. Alternatively, filenames beginning - could simply be disallowed.

Comment: Re:multiple inputs for 4k? (Score 1) 186

by Ed Avis (#47280767) Attached to: 4K Monitors: Not Now, But Soon
That's how the later model IBM T221s worked (with additional converter boxes dangling off the monitor). Each half of the screen was seen as a 1920x2400 display. Some newer 4k monitors work similarly using multi-stream transport (MST). The video card sees two 1920x2160 displays. But there is only one DisplayPort cable. Dell's 24" and 32" 4k monitors are like this. Video drivers usually have special support for gluing the two halves back into a single display, but the extra complication can expose bugs in either the driver or the monitor's firmware.

Comment: Re:Supported (Score 1) 164

by Ed Avis (#47280569) Attached to: Endurance Experiment Writes One Petabyte To Six Consumer SSDs
I think that's what I was saying: a random mixture of disk sizes is not supported by this particular RAID implementation - it will only use the same size across each disk, meaning you are constrained to the size of the smallest disk in the pool. You have to upgrade all of the disks to a larger size before starting to use that size. Btrfs and ZFS sound like they handle it much better.

Comment: Re:Not a surprise (Score 1) 62

by Ed Avis (#47280221) Attached to: Freecode Freezeup
Yes that's right, the listing was deleted if you didn't respond. That tended to bite me as I would only check my personal email infrequently. I think that even if the listing owner disappeared completely, it would still be better to have an entry saying 'hey, this program exists, can you help find it?' and listing the last known whereabouts. But I see your point that you didn't just delete them without warning. Thanks for your work maintaining the site over many years.

Comment: Re:Not a surprise (Score 1) 62

by Ed Avis (#47271497) Attached to: Freecode Freezeup
The trouble with Freshmeat/Freecode was that they aggressively deleted entries when links broke. So if a project's homepage went down it would soon become unsearchable on the site. This reduced the site's usefulness as an archive of known free software. (Much better to keep the archived information and encourage people to fix the links - as a last resort, somebody who downloaded the tarball before the site went down could re-upload it somewhere.) Is there an alternative site which works as a kind of encylopaedia of free software? Github is great and all, but it is a project hosting site rather than an index of all software (which may be hosted externally and perhaps not even maintained in a public git repository).

Comment: Re:Display Port (Score 2) 186

by Ed Avis (#47263817) Attached to: 4K Monitors: Not Now, But Soon
No current DisplayPort standard supports two 4k monitors at 60Hz with a single output. The latest DisplayPort 1.2 will drive a single screen at 3840x2160@60Hz, but current monitors use multi-stream transport (MST) to do so which means the video card sees it as two separate monitors which then must be tiled together - this tends to expose driver bugs. DisplayPort 1.3 will increase the bandwidth but I don't think it has been finalized yet, nor is any hardware available.

Comment: Re:waiting for 8K (Score 1) 186

by Ed Avis (#47262043) Attached to: 4K Monitors: Not Now, But Soon
The IBM T220 was announced in 2001 and had a 3840x2400 resolution, effectively what marketing now calls "4k" plus a little bit extra vertical space. It was limited to 41Hz refresh, though its replacement the T221 a year or two later increased that to 48Hz (and the last model can be overclocked to 55Hz or so). Sadly there were then the monitor Dark Ages when the T221 was discontinued and the world seemed to regress to crappy resolutions like 1440x900. You're right that 2010 was the time things started to look up again, and 8k has been demonstrated as a prototype. 5 years sounds about right; the difficulty with an 8k monitor is not so much the panel (high-dpi panels exist already, and could be cut to a larger size like 30 inches) but driving it. With the current DisplayPort spec several independent cables would be needed to drive 8k at 60Hz.

Comment: Re:Ow, the ignorance (Score 1) 186

by Ed Avis (#47261987) Attached to: 4K Monitors: Not Now, But Soon
Yeah, I wish that there were better alternatives to the normal way of scrolling. Even at 60Hz refresh (and with pretty big font sizes on a 180dpi screen) it is not exactly easy on the eyes to read text as it scrolls. I like the old school way of hitting Space (or PgDn) to move down one screenful. But then you can lose track of where you were in the text. I'd like to see a horizontal red line showing the previous start of the screen, which would fade away over a second or two.

Comment: Re:Get a TV (Score 1) 186

by Ed Avis (#47261705) Attached to: 4K Monitors: Not Now, But Soon
Have you tried 30Hz? It really isn't a big deal for text-based applications like programming and web browsing. Sure 60Hz refresh is nice; it gives you warm fuzzies to know that you're getting a fast refresh rate, and things just generally look cuter and more Apple-commercial-like if the screen refresh is smooth. But it's a hard case to make that it really has an impact on productivity for real work. I'm using Dell UP2414Qs at the moment, and the 60Hz refresh is great (tip: set the colour management to Game mode to eliminate input lag). But before then I used T221s at 24Hz and that was fine too for emacs and web browsing. I've even used a T221 at 12Hz and while I can't say it was the most comfortable setup, it got the job done.

Comment: Re:context (Score 1) 164

by Ed Avis (#47252385) Attached to: Endurance Experiment Writes One Petabyte To Six Consumer SSDs
Right, but while you may well need to archive data for 30 years, that doesn't mean you need to store a particular physical tape or disk for that long. It would make more sense to store the volume for five years and then transfer the data to a new one, to take advantage of capacity increases. Your warehouse full of tapes from 30 years ago might fit in a desk drawer now. So if I wanted to back up to hard disks, I'd keep a pool of them and replace the oldest disk every year or so. Admittedly software support for this is not great - RAID implementations don't always support cobbling together a random mixture of disk sizes which change over time.

Comment: Re:Throw the book... maybe literally at him. (Score 2) 220

by Ed Avis (#47201353) Attached to: NSF Researcher Suspended For Mining Bitcoin
The thing is that mining bitcoins is not really a supercomputer task. It is an "embarassingly parallel" problem - you could get some PCs and connect them over 9600bps serial ports, and it would hardly be any different to using the fastest network to connect them together. There is not that much communication needed between the parts of the cluster. A true supercomputer usually has fast, specialized interlink hardware between the compute nodes so it can work on problems which are somewhat less parallelizable, requiring more communication between the nodes. That is why it is expensive, and expensive to hire computing time on it, and yet it doesn't perform any better at bitcoin mining than a simple-minded farm of commodity hardware. (And for bitcoin mining, either of those will be blown out of the water by specialized ASICs.)
Medicine

Electric Stimulation Could Help You Control Your Dreams 138

Posted by samzenpus
from the lets-get-lucid dept.
sciencehabit (1205606) writes "A new study suggests that mild current applied to the scalp while sleeping can help people become aware of, and even control, their dreams—a phenomenon called lucid dreaming. Researchers recruited 27 men and women to spend several nights in a German sleep lab. After the volunteers had plunged into REM sleep, a state in which people are unable to move and the most vividly recalled dreams occur, researchers applied electrical current to their skulls near the forehead and temples. This boosted neural activity in the frontotemporal cortex, a brain region associated with conscious self-awareness, which normally gets tamped down during REM. Researchers then woke the participants and asked them to detail any dreams they could remember. People who had received 40 Hz of current were lucid in more than 70% of their reported dreams. The researchers suggest that the technique could potentially be used to help people who suffer from chronic nightmares."

The reason that every major university maintains a department of mathematics is that it's cheaper than institutionalizing all those people.

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