I have a bunch of USB A to Mini B cables and a single USB A to Mini A cable. I have lost track of where they come from. The two types both look exactly the same with the USB A side having a white plate inside and the shape of the Mini plugs are the same too. So the only difference is that the Mini B plugs are black inside and the Mini A plug is white inside, like the plugs shown here, but my Mini A looks exactly like a Mini B except that it's white.
What is the difference between my USB Mini B and Mini A cables? Do they have the same performance when plugged between my external hard drive and my computer? If not, which type would be better and how?
Should I trust the shape or the color? Because, again, my Mini A plug looks exactly identical to a Mini B plug except for its white-colored plate inside. So could it be that my Mini A is actually just a white-colored Mini B?
Best Answer
USB specs defined two types of Devices at first. A devices, i.e. Hosts like your pc, and B Devices, i.e. Peripherals like a printer. At first, only standard size existed. Then mobile devices needing a smaller connecter, Mini-B was created. It is still for Peripherals only. Then OTG was added, creating the need for Mini-A (Miniature Host) and Mini-AB (Mixed, OTG device).
So Standard A Male to Mini B Male cables are for use from a Standard Host, to a Mini Peripheral. I.E. Your PC to a Cell phone.
Now, A Mini-A Male to Standard A FEMALE is allowed, as an adaptor, for OTG purposes. Mainly hooking up a standard device to a OTG host. Fairly common now. I have had tablets and phones that came with them in the box. A Mini-A Male to Standard A Male is non-standard as all heck.
The color of the connector on the cable is also defined within USB Specs.
Notably, USB Mini is depreciated and has been replaced by USB Micro for years now.
http://www.usb.org/developers/onthego/london/OTG_mechanical.pdf for an entire breakdown (simple to read) on the cable connector setup, as presented by the USB Implementers Forum.