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Just what good is USB, anyway?

I can't help but talk a bit about my own uses for USB, the universalized successor to just about every other external port save for video that was available on the original IBM PCs. My laptop lacks a parallel port, floppy drive, and the two PS/2 ports, but features three USB ports in their stead. What's hooked up to them? A parallel adapter, a floppy drive, and an adapter with two PS/2 ports. Pure genius, folks!

Then there's the issue of incompatibility. I recall, back at a trade expo in the 1990s, seeing somebody with an OCR wand hooked up to a serial port, feeding data off the port into MS-DOS Editor using nothing but MS-DOS's built-in I/O and the ctty command. Palm handhelds that operated over standard serial ports never required special drivers to operate: simply place the handheld in a serial cradle and hit the HotSync button with the client software running on a PC. With USB, drivers are involved - drivers that Palm has decided not to port to 64-bit OSes, aren't supported under Vista, refuse to install if you don't have an accelerated video card, of all things... Need I go on?

My question is this - what exactly is USB doing that original legacy ports couldn't also do, or that other, driverless, more specific standards such as eSATA and Firewire can't do? Why not instead implement PCMCIA or ExpressCard in desktops, giving devices fast, direct access to the machine's ISA/PCI/PCI-E bus without the need to open up the case and install expansion cards?

Print | posted on Wednesday, 25 June, 2008 7:56 PM | Filed Under [ Gadgets Rants ]

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# re: Just what good is USB, anyway?

I sometimes really wonder about USB: No doubt the standard does have a few useful applications, but they're invariably the exception to the rule. Even then the useful applications could easily be duplicated by pre-existing standards like SCSI and (as you mentioned) PCMCIA, that don't require special drivers available only for Windows 98 on up to so much as work.

Some of the applications are really questionable: USB speakers, for instance. Sound is an analog signal, so the high-speed digital interface doesn't do anything here except bog down the processor with A/D conversions and degrade the signal.

When did USB become so pervasive? Until the Windows XP era set in, nearly every PC (at least) contained a full set of legacy ports, and nearly all the printers, keyboards, and mice for sale used the dedicated ports designed for the purposes. I suppose the influence of Steve Jobs and his "USB way or the highway, backwards compatibility be damned" philosophy on the Mac side of the fence is partially to blame, but it's hardly the only reason.

Perhaps it's a cost-cutting measure: In today's cut-throat market of sub-$1000 computers where nickels and pennies are worth shaving off, it probably costs less to solder six identical USB ports to the motherboard than six different serial, parallel, and PS/2 ports. Can't say that makes me like it any better, but there you go...
6/26/2008 1:17 AM | Andrew T.
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# re: Just what good is USB, anyway?

To my understanding, USB doesn't have any provisions for analog signaling, so the conversion would actually take place on the speakers rather than on the CPU. Even then, USB can't provide all that much power - five volts at 500mA means that your speakers max out at 2.5 watts, and that's assuming they're 100% efficient. Including a power brick for those would almost completely defeat the purpose of USB-powering them...

If I really wanted a true digital signal straight to my speakers, I'd probably use S/PDIF. It's been around for ages, has been standardized across devices and platforms, and is available on everything from sound cards to PS2s.

Ironically, I bought a Creative USB sound card for my dad, whose laptop at the time seemed to have a faulty built-in card (years later we later found that Windows ME was at fault, as 2000 handled it perfectly). It didn't work properly with the system, so for a few years it sat and gathered dust in my closet. Later on a friend of mine had use of it; lo and behold, it failed to work with her system either. The card wasn't even broken or defective; it worked fine with my problematic old laptop for the month or two in between its sound card failure and the time at which the USB interface started overvolting anything I attached to it.
6/26/2008 4:22 AM | Don_HH2K
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# re: Just what good is USB, anyway?

What good is USB? Something you like... it's 'STANDARD'. Then, it became popular. I think enough said.
6/26/2008 9:36 PM | Antony Shen

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