I grew up with a DOS-driven PC AT computer, and frankly I never had problems connecting peripherals to it. For those unfamiliar with the PC AT machines, on the motherboard itself it only had a special socket for the keyboard. An additional controller (or controllers) expansion card would carry COM (serial) ports for a mouse or a modem, an LPT (parallel) port(s) for the printer, and some also had a game port for the joystick. Anything more sophisticated (like a scanner) would come with its own add-in controller card. I always knew which device is connected to which port, it felt like there is some order in the universe, and I never experienced a sudden unhealthy urge to unplug my keyboard from the computer while it's working and thrust it lustfully into a printer port, just for a change. There was no plug'n'play, there was pure plug'n'work. And then came the Universal Serial Bus (best known as USB), which was so tied to Microsoft's Windows, it couldn't even work without it. No wonder, since Intel and Microsoft, the infamous Wintel duo, are among the authors of the USB standard.
In theory, USB was a great idea - a universal port for connecting any external peripheral to a computer, allowing safe hot plugging. However, for the first years there were not many devices that would support it, thus it didn't seem too useful. When I finally got enough things to plug into it, the theory was put to practice, and flaws in the USB design started to manifest themselves, showing their ugliness without any modesty.
First things first, let's take the connector itself. While making up a new universal connector, why didn't they (or him, or she, or it) make it round, so you wouldn't care which side up should it go? Or at least, it could have some difference between its top and bottom sides, like the Firewire connector, so it wouldn't be such a pain sticking it in, especially when the socket is not situated right in front of you.
Next thing is what happens when you plug something into the computer. Whatever they say about plugging and playing, it's never as simple in reality. I'm
never sure
when to do it with a new device. Should I plug it in before I turn on the computer on? Or after, but before Windows has started? Before I installed the drivers, or after? Before the required reboot (plug'n'reboot'n'play scenario), or after? It seems like something irreversibly dramatic will happen if I don't perform the steps of this almost religious device connection routine in the exact order, and this order is never the same for all the devices (because, in fact, devices ARE different). My printer, for example, used to refuse to work when I plugged it in while Windows was running - until I changed its cable. The cable was alright, it came with the printer, and worked perfectly with a different device. So much for a standard, huh.
When I plug something while Windows is running, the device won't start to function immediately. No, the driver must be installed first. Even if I have just unplugged the bloody thing from the neighbouring socket. And sometimes, when it does install that driver, it will ask the user (me) to allow or confirm this installation procedure. The most funny case is when you are plugging in a keyboard or a mouse... with
what am I supposed to click on the "next" button? And wait a minute... why
does a keyboard require a driver at all? It shouldn't, and it didn't - in the glorious medieval days of the DOS. So, all in all, this might be called "plug'n'play", but it's certainly not "plug'n'work".
Now let's talk about unplugging. There are certain situations where I'd want to turn a USB device off without unplugging it. An external hard drive, a web camera - anything I use rarely. Despite the assumptions of the system designers, the computer case's backside is not facing the user. Quite the contrary, in fact. So it is NOT convenient to unplug a device just to turn it off. And plugging it back in the moment you need it, is hardly easier. In Windows I can do a "software unplug", but I can't do a "software plug in". If I disable a USB device, I'll need to actually unplug it and plug it back in to re-activate it. If you'd tell this to computer users some 20 years ago, you'd cause a lot of laughs, but today it's a reality many people don't even question - they take it as the only way it can be. I know that that's probably the Windows' fault, not the USB, but you can tell both were backed up by Microsoft - it's so hard to differ one from the other when it comes to bugs.
Next thing is the Hubs. More and more things these days are made for USB, and it is impossible to have enough ports for all the things you'd use. Mouse, keyboard, display, external drive, flash drive, card reader, web camera, photo camera, PDA, scanner, printer, copy protection dongle... There are lamps for USB. Soon coffee makers would roll out USB-equipped. And since you can't chain-connect USB devices like you would with SCSI, you need hubs, as if it's a local area network. A hub itself looks harmless and pretty cute, but that is until it is wired up. With all the cords sticking in and out of it, it would certainly want to fall off your table, and plugging in and out of it is never a pleasant process. And of course, you must have an extra AC adaptor for it. How convenient. I just love to see all those AC adaptors around me, don't you? There just can't be too much. Yes, I
am being sarcastic.
The biggest problem with hubs is that they are mostly made by "third parties from the third world", companies you've never heard about before, and so many of the hubs you find are cheap in more way than one. If you browse through user reviews of USB hubs on the 'net, you'll find such negative experiences as problematic Windows boot up, system freezes, blue screen errors, or even devices got permanently damaged by a faulty or low-quality USB hub. I myself often get booted up with my mouse off. I have to plug it out and into the hub to reanimate it. If I plug certain devices into the hub, some of the others stop functionaing - and I never know how to tell if the hub will "pull" the thing I'm going to plug, or not. So, a hub looks like a mess, and feels like a mess.
Another disadvantage of USB I found out recently is connected with professional level keyboards, which allow handling of multiple simultaneously pressed keys (important for typists and gamers). It turned out that with PS/2 connector those keyboards can handle unlimited number of keys pressed at the same time, but with USB they are limited to 6 keys maximum. So much for a replacement.
A huge disadvantage of USB over traditional connectors such as COM port is its drivers. Older system have no built in support for USB, and until Windows is boot up, anything USB won't work, which is especially sad with hard drives and keyboards. Modern systems come with limited "legacy" support for keyboards, mice and/or external media via USB without drivers (via BIOS), but it's still not as straight forward, simple or reliable as it was with legacy connectors, that required no drivers, no bulky firmware, and would be natively supported in the operating system. With COM you could make your modem dial a number just by sending a simple text phrase right from the prompt. So, I don't think that USB will ever replace connectors like PS/2 or COM, just because it can't.
So, USB, so nice in theory, in my practice always turns out to be
not reliable,
not simple to use, and
not completely universal. It can't replace all legacy peripheral connectors, and it was co-designed by Microsoft. This is basically what I hate about it. Otherwise it's a truly inspiring technology, for sure. After all, it did inspire people to make USB electric blankets, toothbrushes, electric shavers, coffee heaters, fans, and even
this mysterious device.
As for alternatives, I quite enjoyed working with Firewire, never having problems with it, although my experience is very limited; there aren't many devices for it. A recent announcement of Light Peak technology developed by Apple sounds promising. I'm looking forward to seeing a solid replacement for USB, especially if it is designed by Apple. I only hope it won't be as expensive as a Mac ;)
