You use a "regular" USB cable for the external USB hard drive.
http://en.wikipedia.org/wiki/Usb
A "regular" cable has Type A on one end, Type B on the other end.
Type A plugs into the computer. Type B plugs into the enclosure.
You can verify this for yourself, by looking at pictures of the
drive enclosure you're buying. See if there is a "square connector hole"
for the Type B.
*******
The Laplink cable is, strictly speaking, non-standard. It has
Type A on both ends, and a "blob" of electronics located somewhere
between the two connectors. The "blob" provides logical isolation
between the two computers ("hosts"). We're not sure about the
electrical properties - if using Laplink, I would recommend the
two computers be on the same power strip. That seems safest.
That's because of the potential for a ground loop.
Some laptop external drives, come with absolutely illegal cables,
with Type A male, on all ends. You should *not* connect two computers
together with that. Of course, the temptation for manufacturers
to do something that stupid, was just overpowering, and they
couldn't help themselves.
USB is meant to connect from host to peripheral, not host to host.
The Laplink cable solves that problem, via logical isolation.
The "blob" of electronics, forms an electronic mailbox. The
software on one side, sees the mailbox, and leaves a "letter"
in the mailbox. The computer accessing the other side of
the blob, notices it just received a "letter" in its view
of the mailbox. In this way, two hosts communicate with
each other, without violating the design intent of the USB
architecture. The computers think they're talking to a "mailbox
peripheral", so each computer thinks it is a host to peripheral
situation.
Unfortunately, there are other USB cables with "blobs". They're
active repeater cables. In that case, there's a male and female
connector on either end of the cable, and the blob houses a
one-port-hub (USB hub) electronics. Active repeater cables are
used for making a "USB extension cord", so you can connect a
web cam a couple of rooms over. And a repeater cable, since it has
male on one end and female on the other, cannot be used
to connect two computers directly to one another. Only
a Laplink cable can be used for that. And a Laplink cable
cannot function as an extension cord, because again, it
has the wrong connectors on the end.
As long as cable makers avoid providing all manner of adapters,
then the user can't get in trouble. By violating the rules,
then we end up with a mess, where the consumer needs tech
support, every time they reach for USB. Which is not
a desirable situation. The connector types were originally
intended to make the cabling "foolproof".
I know this is only making matters worse, but thought I'd
provide a little background.
Paul
