|All USB ports built into the mboard, and USB ports connected by adequate wiring to USB headers on the mboard, and all USB ports on drive CONTROLLER cards you install in slots, are able to supply up to and including the standard 500ma (1/2 amp) specified in the USB specs.|
However, sometimes the wiring to USB headers on the mboard is NOT adequate.
A USB hub, or a hub card in a slot (they used to be available for desktop comuters when there were was only USB 1.x but I don't think anyone makes them anymore), of the type where more than one USB port connects to one port directly connected to a mboard USB port, has to share the 500ma the one mboard port provides with all the ports, unless the hub is a "powered" one that has an additional power supply that plugs into it, but even so, some USB devices will NOT work with a "powered" hub of that type.
Most USB devices do not draw very much current, but some do. Printers, scanners, and multifunction printer/scanner/etc. devices draw more current, and external drives connected by USB often draw the maximum current when they are starting up.
External hard drives cannot get enough current from one USB port alone.
2.5" external drives require 500ma from each of TWO USB ports when starting up, or 500ma from a USB port and 5v 500ma from another power adapter (that's for current laptop drives, none of which draw more and an amp when starting up - older ones may require even more current).
3.5" external drives connected by USB must be connected to a USB port that can supply 500ma and they must have an external power adapter connected to their case.
Most if not all USB 2.0 devices are backward compatible with USB 1.1 standards - they still work, the difference being if you have it plugged into a USB 1.x only port (connected to a USB 1.x controller) the max data transfer rate is much slower.
Some older mboards have some ports that support USB 1.1, some that support USB 2.0, which also supports USB 1.x, but newer mboards have ports that are only USB 2.0, which also supports USB 1.x.
If the mboard has USB 2.0 hardware support, ALL USB devices should work when connected to USB ports built into the mboard, and USB ports connected by adequate wiring to USB headers on the mboard, and all USB ports on drive CONTROLLER cards you install in slots, IF your power supply is okay, and if the wiring to headers is adequate, and if you don't have an IRQ sharing problem, but some devices will NOT work in a hub of the type that connects to only one mboard port even if the hub is "powered".
See response 3 in this:
You can have other problems with USB 1.x .
Your 2-port USB PCI card (Opti Firelink USB 1.1) is a probably a controller card, not a hub of the type that I am saying can cause problems.
USB 1.x (only) uses a chipset that supports either OHCI standards or UHCI standards, not both.
Some USB 1.x chipset brands work with more devices than others do - e.g. an NEC chipset is a good one, earlier Via ones will work with fewer devices. Some USB 1.x devices, rarely, will only work properly if the chipset supports OHCI standards; some only work properly if it supports UHCI standards.
See this site for more info:
If you have problems when you have a device plugged directly into the Opti Firelink USB 1.1 card, or a port directly connected to the mboard, or in any case, you are better off getting a recent PCI USB 2.0 controller card, that has as many as 4 external and one or two internal USB ports, and using it in place of or in addition to the Opti Firelink USB 1.1 card, rather than you using an external hub, powered or not.
The USB 2.0 controller cards are backward compatible with USB 1.x devices, and Windows detects both USB 1.1 and USB 2.0 controllers when you have a USB 2.0 controller card, and the USB 1.x support of controller chipsets has improved over the years such that it is much better than it was in the past and you are extremely unlikely to have problems because a device requires the controller to adhere to OHCI or UHCI standards.
PCI USB 2.0 controller cards are very cheap these days - as little as $30 or less.
If one has a laptop, PCMCIA (PCI Cardslot) USB 2.0 controller cards, or if you have a newer laptop with no PCMCIA slot, ExpressCard USB 2.0 controller cards, are available cheaply, but they often require you plug in an external power adapter into them if a USB device requires more power.
Be aware that there may still be PCMCIA cards out there that are merely USB hubs - DO NOT buy one of those. If the description doesn't say it's a controller and will support drawing up to 500ma in each port even when all ports are being used, and/or if it doesn't have a port to plug in an external power adapter, look elsewhere.
However, Win 98SE does not natively support USB 2.0 (it was not built in) - it was not available when 98SE came out (it wasn't when 2000 or XP first came out for that matter) - you must make sure the USB 2.0 controller card comes with Win 98SE or 98SE/ME drivers - many do not.
You can get generic USB drivers from places on the web that will work with the USB 2.0 card in 98SE, but it's preferable for you to get them with the card.
Generic USB 2.0 drivers for 98SE (they should work for ME too):
The 2.x drivers support most USB 2.0 devices but DO NOT include support for USB 2.0 controller chipsets.
I'm using those and they work for most things, except Apple devices e.g. iPod whatever (at least, they don't for the drivers version I'm using).
There is no iTunes support for operating systems older than XP, or possibly 2000.
They support many USB 2.0 devices no 98SE drivers are available for. e.g. some card readers, Kingston Traveller flash drives, other flash drives.
The 3.x drivers support most USB 2.0 devices AND most USB 2.0 controller chipsets.
They also have them for Win 98 (Gold, the original version - the drivers for it are indentical to or like those for Win 95 OSR2 or later - 98SE/ME drivers are different).
"****4 USB port A type upto 400mA and auto current sharing by device request****"
That doesn't even meet the standard 500ma max spec for one port.