Gold plating is truly significant. It has made Radio Shack and Monster Cable millions of dollars. On the other hand kajillion electrons have cared less.
Gold plating is truly significant. It has made Radio Shack and Monster Cable millions of dollars. On the other hand kajillion electrons have cared less.
LOL I work at a Radio Shack. Actually our gold-plate cables are way cheaper than Monster. Don't buy super wootsy-poot oxygen-free high-test magic fairy-dusted cables for digital signals. This includes HDMI. Gold plating does in fact inhibit corrosion and makes for a better contact, but that doesn't matter on digital. About the only time to buy a better-than-average cable is analog Hi-Def like RGB.
Well, since you work at Radio Shack I'll stop making wisecracks about them (they are certainly convenient). I will though mention the "In Praise of Monoprice (http://geekhack.org/showthread.php?t=6017)" post has some alternatives and a nice cable discussion.
DVI can handle longer distances surprisingly well - I've got this 50 foot cable running from a wiring closet to the PC above running 720p. I read the specs too (vague as they are about distance) but decided to ignore them. Works flawlessly.
Another use for the RipOmeter!Show Image(http://geekhack.org/attachment.php?attachmentid=3145&stc=1&d=1247407282)
There are many advantages to moving the media PC out of the living room. Chief among them for me it allows me to reuse an old PC (AMD X2).
I would think that, by its polled nature, USB would potentially be higher latency then PS/2.
If it's polled faster than it takes to transmit data over PS/2 (PS/2 is incredibly slow, I don't know if USB polling rates are limited), latency is lower. Still, the whole latency business is horribly overstated in my opinion.
Speaking of gold plating, almost everything has already been said, so I'll just add one thing: Irrespective of its merits, gold plating the outer portion of a USB connector won't do anything at all. No signal or even current is transmitted over it, it's just to ground the shielding. Shielding needs to be grounded, but that's it basically. If gold-plating anything is especially useless, it's the shielding connector.
-huha
Well, I've been trying to convince my wife to get a bigger TV but this isn't probably the winning argument. What about HDMI - wouldn't I be OK with that and reasonably thick cables?? We're talking 50 feet.
Latency is used as a marketing ploy to get gamers, i.e. teens/twenty-somethings to buy lots of overpriced crap.
I don't quite see the point in having gaming keyboards with such tiny latencies even audio applications don't give a damn. When your keyboard has less latency than tolerable for realtime audio (about 10 ms), you really ought to wonder.
That said, as far as latency in games goes, I think USB could be better off there. I've calculated the maximum key press/release rate of PS/2 but am too lazy to search for it; I think it was about 250 Hz. USB has the advantage of transmittting all keys in one single packet, i.e. each poll cycle, whereas PS/2 needs to transmit them sequentially. So if you want to do that duckjump while throwing a smoke grenade, ordering a pizza and reload, USB could well be faster than PS/2 because all keystrokes are transmitted at once.
I highly doubt the average game logic could make anything out of it, though.
-huha
Either way, do you know what speed the PS/2 clock runs at?
And in all technicallity, even with USB the keystrokes are sent one by one. After all, it is a serial connection.
Latency and bandwidth are somewhat intertwined. If you run out of bandwidth, latency will suffer. USB has enough bandwidth to bear the large protocol overhead, so latency is just influenced by polling rate. PS/2 has enough bandwidth for normal purposes, but bandwidth does become a limiting factor for latency when doing theoretical calculations.
That said, you miss one thing in your calculations: PS/2 needs some "rest" in between the keystrokes. Search for "PS/2 protocol" or something like that on the web, there are a few sites with a bit of in-depth information.
-huha
In practice the differences are not likely to be that large since key scanning typically occurs in about 20 ms intervals (much larger and you may get key transposition problems, below 10 ms and you may get in trouble with key bounce), so that alone means an average delay of about 10 ms (or 50 ms for the Das III). Ghost key detection has to be performed as well.
The main problem for USB boards (at least some of them) seems to be running out of processing power which forces key scanning to be slowed down.
Well key bounce isn't really an issue even if it does happen. It's very easy to program the controller to ignore state changes in pressed keys for 10ms or however long the switches need. Like, really, really easy. In fact I don't see how it would even increase costs. All it needs is a few extra gates and flip flops which I'm sure that their current ICs have room for - and that's only if they choose to program it in hardware.
You don't want to ignore state changes due to RF noise. The keyboard matrix is essentially a fancy antenna and can pick up all kinds of wonderful stuff. If the controller's not programmed to ignore short state changes and rather ingegrate state over time to check whether the key has been pressed, you might get random keypresses, which is somewhat undesirable.
-huha
Manyak writes:
> Quote:
>
> Originally Posted by ripster View Pos
> Well, I've been trying to convince my wife to get a bigger TV but this isn't
> probably the winning argument. What about HDMI - wouldn't I be OK with that and
> reasonably thick cables?? We're talking 50 feet.
>
> HDMI cabling (and signaling) is identical to DVI. But I have a feeling that you'll be
> able to get away with it. I'm sure that if someone actually made a 50ft DVI cable it
> was made properly. Besides, that cable you've got is thick as hell for DVI.
>
> Besides, even with a few bits of the signal lost you won't be able to notice the
> difference (especially not on an LCD, since the panels don't have the gamut to display
> true 32-bit color anyway).
This is only true for DVI, where the bits transmitted correspond to
actual color values of the supbixels. HDMI OTOH transmits an encrypted
stream which will go out of sync as soon as single bit flips. This
results in a blanked screen for fractions of a second, which is much
more noticeable than a single off-colored subpixel out of millions for
1/50th of a second.
No HDCP with my setup - I have a PS3 upstairs connected to the TV. And the copy protection?? Well, that mysteriously disappeared somehow from my DVDs. AnyDVD might have had something to do with that.
The datasheet of the Elan EM78M611 microprocessor (http://www.datasheetarchive.com/EM78M611-datasheet.html) found inside the i-Rocks KR-6230 allows shedding some light onto the process of key scanning. Apparently its A/D inputs can be scanned between 47 times and 1500 times per milli(!)second. Should be plenty for a keyboard.
Even in the old VT100 terminal keyboard, a key has to be registered for at least 2 scanning intervals in order to be considered a valid key press.