Why Apple initially chose 30-pin dock connector:
The Future Of Apple’s Dock Connector [Feature] | Cult of Mac
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The problem with USB, though, is that it was designed as a protocol to standardize PC peripherals: keyboards, mice, digital cameras, printers, disk drives, that sort of thing. In other words,
USB expects that you’ll be using a traditional desktop computer to load drivers to access an accessory.
The problem with USB is that it expects you’ll be using a traditional desktop computer at one end.
And that’s the problem. Your iPhone, your iPad, your iPod… sure, these are all computers, but they don’t load drivers. In conventional desktop computing terms, these are still accessories. So how do you get one accessory to talk to another accessory without drivers?
That’s where Apple’s 30-Pin Dock Connector comes in.
It allows an iPhone, an iPad or an iPod to talk directly to compatible accessories, no drivers required. It’s the soul of Apple’s billion-dollar iPod, iPhone and iPad accessory empire.
The 30-Pin Dock Connector is what allowed Apple to turn the iPod, then the iPhone and iPad, into the hub of so many people’s digital lives.
Thanks to the Apple Dock Connector, we have cars that can speak with our iPhones or iPads, televisions that can suck movies from our iPods and display them 50-inches high, and an endless and affordable array of iPod-compatible toys, peripherals, accessories and speaker docks. It’s telling that the one iDevice that doesn’t ship with a 30 Pin Dock Connector — the iPod shuffle — is the one that has a negligible number of third-party accessories made for it: the iPod shuffle is the only iPod that uses straight USB instead of 30 pins.
We’ve already seen that a USB connector only has four pins: two for data, one for power and one for ground. It’s up to a connected computer to be able to load drivers to be smart and powerful enough to translate the data coming from a USB device into a format it can actually work with.
The 30-Pin Apple Dock Connector works quite differently, though. Each pin has a specific function, and all a compatible accessory needs to do is watch what data is coming through the specific pins it needs to provide that device’s functionality.
Think of the Apple Dock Connector like a lock, and a compatible accessory like a key. In any lock, there are a number of tumblers; for a key to open that lock, it needs to be precisely cut so that its ridges trip those tumblers and then unlock, say, a door or a box.
That’s how the 30-Pin Apple Dock Connector works.
While two of those thirty pins do provide USB data-in and data-out for the purposes of syncing, the rest have very specific functions. The result is that if you plug your iPhone into, say, a speaker dock, the speaker dock’s connector is configured so that it only trips the pins it needs: in this case, audio out and power in. An accessory made to display video from your iPod classic on your TV, on the other hand, will be configured to only watch the video out and audio out pins. And so on.
The original 30-Pin Dock Connector was a remarkably future-proof design, and Apple has added functionality to many of the blank pins over time; until now, there’s a pin for nearly every function an accessory could possibly want to provide.
The benefits for accessory makers are huge, because they don’t have to make devices with power-hungry CPUs to try to figure out and translate all of the data coming in and out of an iDevice into a format it can actually use.
But there’s a catch. While the Apple Dock Connector has lasted almost a decade without a significant design change,
it’s one of the bulkiest components of an iPhone or iPad. That makes the Dock Connector a big bottleneck when it comes to slimming down future iPhones and iPads and giving them better battery life. After nine years, it’s in Apple’s vested interest to make a smaller, better Dock Connector.
In 2012, many of the pins on the 30-Pin Apple Dock Connector are reserved for obsolete technology.
A full eight pins on the 30 Pin Dock Connector are dedicated to maintaining Firewire compatibility. The only problem is that Apple has abandoned Firewire in favor of USB 2, Thunderbolt and now USB 3. It’s pretty much a dead technology. All of those pins can be reclaimed without impacting consumers or accessory makers (except in extremely marginal cases).
That’s not all. We’ve also highlighted pins 8, 9 and 10, which seem to exist only to provide pretty marginal video-out functionality to a handful of iPods. Between both the Firewire pins and the legacy video-out pins, we can easily shave 11 pins off of a 30-Pin Apple Dock Connector, leaving just 19 pins total.
That’s why the best option available to Apple is to just drop the pins accessory makers aren’t using from the existing Apple Dock Connector. Doing so will allow Apple to make the connector at least 37% smaller while still maintaining backwards compatibility by selling a 30-Pin-to-19-Pin adapter, which, of course, will also make Apple a tidy profit.
All the while keeping relationships intact with both accessory partners and customers who might otherwise have seen thousands of dollars worth of their “Made for iPod”, “Made for iPad” or “Made for iPhone” accessories become obsolete overnight."
