Powered USB Hub

Get a PCI card that adds USB functionality.

I was all set to buy a hub when I came across a computer lying on the sidewalk, and it had a USB board inside. No need for a hub after that, but I do get more USB ports.

Of course, if there was a special reason for a hub, you didn't mention it.

Michael

annoying having to crawl around trying to find a usb port on the back of a computer a hub on the table easier

-Lasse

Let me know when you find some four port low profile USB boards laying around, for salvage. I need two. :)

I use extension cables.

Eeek, Senior moment? Well, I sure didn?t get the full 667mbs theoretical thruput, but is was somewhere around the USB port speed. Which must have been ~400mbs, not 200mbs. I should check it again. But the point was that it worked with out a hitch.

Cheers

-Lasse

Yes, and while we're on that subject, I had earlier stated that 1.1A was the I(lim) on USB 2.0. Apparently, it's only 500mA. (Mental note to self: Next time go get that really book you ordered for the USB project a couple years back.)

I was somewhat pleased to see that the USB powers that be have a (farily) new addendum out to cover non-enumerated dedicated charger- only ports. I read the limit for those would be 5 amps, but not sure if that is officially adopted, or what hoops one has to jump through to build a device that would be compliant with the addendum. Nice to see the standard evolve in any case.

'Cept for really cheap crap, i haven't had any hub problems.

You may wish to get some USB 3 hubs, but they are never more than 4:1.

Not a lurker, i post.

?-)

long

with

other

correlation

that

A USB 2.0 unit load is 100 mA max. A device may use up to 5 unit loads.

from 7.2 power distribution.

The Standard is available here:

USB 3.0 Standard is there also.

?-)

--

current

But

See my recent post for USB standards links.

?-)

wrote

all

bigger

on

To say the least. The required 8/10B causes 25% overhead minimum.

?-)

If you can't get 'em for free (and shipping is never really free), these are pretty cheap and have five ports:

That's not low profile. I bought two of these from another seller. Three weeks later I got an e-mail stating that the entire shipment was defective, and they refunded the money.

This is interesting:

Wow, that is.

I guess there's a lot of those "industrial" keyboards (either ruggedized or with extra keys or whatever), barcode scanners, etc. that have PS/2 interfaces and aren't going away any time soon? So on new builds it ends up being easier to stick in a card like that than to pick from the small number of motherboards that still have PS/2 keyboard/mouse support?

I've seen plenty of PS/2 to USB converters for keyboards and mice, but for industrial PCs I can see that a PCI card might be a bit more attractive.

There are gender flippers both ways.

The difference with this card is that it goes under the PCI bus and gets an interrupt assigned to it as in the legacy method and will almost always underlying OS support, whereas a USB to PS2 device will not get an interrupt and *has* to also have underlying OS support for an HID device.

It might even be Jorge proof. ;-)