Wikipedia:Reference desk/Archives/Computing/2013 July 2

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July 2

interference to heart rate monitor

There is nothing wrong with my watch (forerunner 305). I am just wondering, will the heart rate monitor work when I am using the elliptical in the gym? It is a heart rate monitor that is worn below the chest, and pairs with the watch (it is not attached to the watch). The elliptical is about 2-2 1/2 feet from a television. — Preceding unsigned comment added by 99.146.124.35 (talk) 02:19, 2 July 2013 (UTC)

I think it's very unlikely that a TV monitor will generate strong enough electric fields to mess up a heart rate sensor that you wear on a strap that goes around your chest. Are you having problems? Looie496 (talk) 02:27, 2 July 2013 (UTC)

As to whether the sender in the chest strap will be understood by the receiver in the elliptical machine, the answer is "maybe". There's a variety of wireless protocols that such equipment uses - ANT+ seems to be the dominant (the closest there is to a standard), but other systems use other schemes, some of them proprietary. The Garmin Forerunner article suggests they all do ANT+; you'd have to see what the brand of elliptic machine uses. I have gotten a Target Fitness band working with a Life Fitness bike, but neither has markings as to how this worked. In that case, a Bluetooth-like "pairing" paradigm doesn't seem to hold, as my heartrate was shown in the two adjacent bikes too - so presumably each bike was picking the strongest radio signal, if any. Sensibly, the Life Fitness equipment would ignore the radio signal and use the signal from its contact heartbeat sensors (if there was one) - so the people riding those adjacent bikes could grab the handlebars and override the display of my heart rate with theirs. -- Finlay McWalterჷTalk 10:17, 2 July 2013 (UTC)

HP 9845C screenshots?

At the homepage about HP 9845C. There are some really nice pictures [1], [2], and at the demo [3], [4], etc. Is there any free versions of these? Electron9 (talk) 13:10, 2 July 2013 (UTC)

Wow those are pretty neat! So you mean free versions of those exact pictures? I don't think that would be possible - you would have to claim fair use. There might be similar images that are free but those, probably not. --Yellow1996 (talk) 16:10, 2 July 2013 (UTC)

⟍⟍⟍⟍⟍⟍⟍⟍⟍⟍⟍

What do we call this character? ⟍ is a redlink, as is Box (typography). 2001:18E8:2:1020:5DD6:98CF:4B3B:E815 (talk) 13:28, 2 July 2013 (UTC)

mathematical falling diagonal -- Finlay McWalterჷTalk 13:31, 2 July 2013 (UTC)

Hm. On my screen, it's a little rectangle, not the character that displays on your link; I guess I don't have the right font. I was meaning to ask: what's the "official" term for the little box that displays when you don't have the right font installed? 2001:18E8:2:1020:5DD6:98CF:4B3B:E815 (talk) 13:35, 2 July 2013 (UTC)

Exactly. More generally, if a page contains a unicode character that isn't represented by an available font, your browser will draw a placeholder box. Some browsers (e.g. Firefox) will show the hexadecimal value of the character's codepoint (27CD in this case) inside that box, so even if you can't see what the character is supposed to look like, and it's possible to search unicode info sites like the one I listed above for the character by its code. See fallback font and Unicode's "Display of Unsupported Characters" advice. It doesn't render correctly for me either, btw. -- Finlay McWalterჷTalk 13:43, 2 July 2013 (UTC)

So is the box image officially a "placeholder box", "missing glyph", a ".notdef glyph", or something else, or does it not have an official name? 2001:18E8:2:1020:5DD6:98CF:4B3B:E815 (talk) 13:47, 2 July 2013 (UTC)

Beyond those there's also "substitute character", and uncode suggests using U+FFFD � "replacement character" (see Specials (Unicode block)). -- Finlay McWalterჷTalk 13:50, 2 July 2013 (UTC)

Freezing on a Mac

I have a MacBook Pro and recently have experienced freezing when watching films with DVD player and when watching videos or listening to music in iTunes. With the music in iTunes, there is just silence for a few seconds, before the music eventually starts playing again, at the same point where it stopped. With the other two problems, the video freezes but the audio tends to continue. Can anyone suggest anything? A similar issue happened to me a while back with just iTunes and it was solved by repairing disk permissions but that hasn't helped this time. Thanks. meromorphic [talk to me] 20:43, 2 July 2013 (UTC)

Have you tried reinstalling your video drivers? --Yellow1996 (talk) 20:34, 3 July 2013 (UTC)

You really don't do that on a Mac ;-). Check if the Activity Monitor shows some unusual activity. Sometimes a rogue process uses too much system resources. --Stephan Schulz (talk) 20:44, 3 July 2013 (UTC)

Ah - I see! I was actually going to affix "I was hoping that an actual Mac user would respond, but..." to my answer; and luckily for the OP, one has! ;) --Yellow1996 (talk) 21:10, 3 July 2013 (UTC)

Well, I'm more of a UNIX head, but PowerBooks/MacBooks have for a while been the best UNIX laptops one could buy. Not modern Ultrabooks with Ubuntu come close, but not yet close enough... --Stephan Schulz (talk) 21:55, 3 July 2013 (UTC)

How much RAM do you have? How much free space on your startup drive? Are you running a lot of other programs at the same time? It kinda sounds like your system is thrashing. --Navstar (talk) 19:36, 5 July 2013 (UTC)