Wikipedia:Reference desk/Archives/Computing/2016 October 30

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October 30

.iso files don't get burned

I have a Windows 7 laptop. When I click on an .iso files the system shows it's readiness to burn it to blank disk. I put in a blank DVD and trigger process. But after all the show that disk is being written to, it turns out that disk is blank (though a closer visual inspection of DVD shows that slight darkening of tracks that for a moment makes one believe that data has been written to it.) But put it back in computer and it's empty. Why so happens ? Some overlook on my part in contemplating the process ?210.56.108.118 (talk) 15:48, 30 October 2016 (UTC)

Did you write click on the iso, select burn, and then select the destination drive? Graeme Bartlett (talk) 03:46, 31 October 2016 (UTC)

Another point to check - does the ISO file match the medium? You're not trying to burn a CD ISO on a DVD, or a DVD-DL ISO on a single-layer DVD? Tevildo (talk) 16:46, 1 November 2016 (UTC)

Bit and Qubit Register

Two part question:

1. I'm not really sure what a bit register is or what is so special about it. It just seems like a bunch of bits in a row! Could someone explain somewhat intuitively what it is and why it is important?
2. Going on with the bit register, I'm reading about quantum computing and a "qubit register" was one thing that came up. What is this/why is it so special? Again, this just seems like a bunch of qubits in a row. I do know that it can be written like |A>|B>|C>...|Z> or |ABC...Z> where A, B, C,...,Z are qubits, but I don't really understand intuitively what is going on here.

Any help would be appreciated, thanks! Hnerd (talk) 19:58, 30 October 2016 (UTC)

You can look at our articles Processor register and Quantum register, though they may not be helpful. Hardware register and flip-flop (electronics) may be more useful. You are correct in that they are a bunch of bits stored in a row. They usually have facilities to do things with the bits, such as shift register or other bitwise operations. They will have ways to load, and store values, ways to test what is there, and likely ways to clear them to all zeros. Graeme Bartlett (talk) 03:40, 31 October 2016 (UTC)

This article shows an animation of a small 4-bit register. AllBestFaith (talk) 17:53, 1 November 2016 (UTC)

Waiting for USB-C

I'm thinking about buying a high-end Lenovo X1 Yoga laptop (the model with the OLED screen and 16 GB RAM (which unfortunately only comes with the i7-6600U which I wouldn't choose if I could get more than 8 GB on this machine with an i5, but the RAM is soldered and configurations are limited)), and was wondering if I should really be waiting until the next gen comes out with a USB-C port. Can you guys point me to 1) a site that predicts when the next X-1 Yoga will be available based on Lenovo's release cycle and 2) a description of what I might be missing in a year or two by having a laptop with three USB 3.0 ports but no USB C. It seems that the big USB-C advantage is having a single cable type and single port type for multiple purposes. Is this all just a matter of convenience, or is there something that I will likely be wishing I could do a year or two from from now, "If only I had USB-C."? -- 66.203.139.164 (talk) 22:26, 30 October 2016 (UTC)

Yes, it's mostly convenience, as well as future-proofing. USB Type-C is an attempt at making "one cable to rule them all" for modern external communications buses. You likely won't miss much unless you're devoted to getting all the latest bleeding edge gizmos. At most you'll need a hub or adapter, if you get something that only has a USB Type-C connector and want to connect it to your laptop. --47.138.165.200 (talk) 03:23, 31 October 2016 (UTC)

See also this and this. --76.71.5.45 (talk) 05:34, 31 October 2016 (UTC)

While what you right is mostly correct, there are some things which will be different. For starters, if the device is USB type C, it may also be USB 3.1 gen 2 so will be capable of double the data rate, although I suspect it'll be quite difficult to find a device where you can notice this.

Additionally, many fancier Intel based laptops with type C also have Thunderbolt with it. Does the device you mentioned have Thunderbolt at all? You mention high-end so I would expect it to. Are you likely to want to use it? Thunderbolt (interface)#Thunderbolt 3 also has several advantages over earlier versions. Outside of certain niche products, Thunderbolt doesn't seem to have been that successful but it's possible this will change with USB type C. Notably, there's currently a big move towards support external GPUs which so far haven't been that successful.

Some (many?) laptops using type C also seem to support 1.5A, or even 3A for charging devices. Type A adapters are not supposed to enable these power delivery modes, it's incredibly non-compliant and generally results in scathing reviews from Benson Leung [1]. You could use an external power adapter (something you plug into the wall) or power pack (something with a battery) with a type C port to charge your devices, but that's more than just a simple adapter and so may be annoying to take around with you and use. While there are various means to deliver more than 500 or 900mA over type A, this relies on a variety of different signalling methods to indicate support. Laptop support for these isn't always good. Worse, device support for these can be spotty. Perhaps not surprising, Apple's method which allows up to 2.4A is best supported. But it seems this is actually being abandoned by some devices which use type C. E.g. from what I've heard, the Nexus 5x does not support these methods so is limited to 500 or 900mA over type A unless you use a non compliant adapter. Note that even if the laptop supports outputting more than 500 or 900mA over its type A port, it's possible it expects the signalling methods to tell it and won't be happy by a non-compliant passive adapter which simply tells the device it can draw more. In other words, without type C, newer phones and tablets may charge slowly off your laptop but could potentially charge a fair amount faster with type C. </p

It's possible charging advantages could be in reverse. Some laptops, especially those with Thunderbolt 3, seem to support charging over the type C port, even if they have their own charging port. They may need some form of USB higher voltage power delivery for this to work. And from what I've read implementations are a bit hit and miss and the moment, with limited info on what's required, so some devices will be able to charge some laptops but not others. Some even seem to use non standard methods although I think a lot of these were designed before USB power delivery over type C was finalised. Still if it does work, it may mean you can use a power pack you have for your phone, or an adapter to charge your laptop in a cinch.

There are a bunch of other scenarios which could arise e.g. relating to DisplayPort and HDMI. A minor point but outside of charging, the simplest and most common adapters for type C are small type C plug to microUSB socket. These are easy to carry around and work well because microUSB (to type A) cables are fairly common or you can carry your own. You can also carry a type C to type A cable. What is a lot less common is type C to type A USB3.0 cable or adapter. You could get one and carry it around but you may want to carry a type C to microUSB adapter with you at all times (to make it easier to attach to chargers and other stuff with microUSB) and maybe even a microUSB cable (especially if you have other devices you take with you) and maybe even a type C cable (if there's anything type C you could attach it to. If you don't carry a USB3.0 cable or adapter, this means if your phone or tablet does have USB3.1 gen 1 (i.e. USB3.0) or USB3.1 gen 2 speed support, you are potentially not going to be using it with your laptop when you're carrying it around. Or to put it a different way, especially once you have a phone or tablet or whatever with type C and assuming you ever want to attach it to your laptop, not having type C on your laptop is likely to mean a lot more adapters than having a laptop with type C but no type C or tablet.

Nil Einne (talk) 07:58, 1 November 2016 (UTC)

Thank you. -- 66.203.139.164 (talk) 16:11, 2 November 2016 (UTC)