Skymaster PCI USB card

Review date: 20 April 1999.
Last modified 03-Dec-2011.


Universal Serial Bus (USB) is, finally, turning into something worth having. There are USB mouses, USB speakers (and adaptors for ordinary speakers – I review one here), USB cameras (like the Logitech Quickcam Home), USB scanners (like HP's ScanJet 4100C) and, of course, USB hubs (I review one here and a funkier one here) to tie it all together.

Which is all very well, if you're lucky enough to have a PC with USB ports. But what if you don't? Do you have to get a whole new motherboard?

smusbcard160.jpg (5502 bytes)

Thankfully, no. All you need is a free PCI slot, if you buy one of the several USB port adaptor cards that are now available. One such is Skymaster's masterfully titled "PCI to USB card", which gives you two USB ports, just like those provided on current motherboards, and works in any PC with a USB-aware operating system.

This pretty much means nothing but Windows 98, at the time of writing; Linux has limited USB functionality, and the rest of the popular PC operating systems, including earlier versions of Windows, are a non-starter. Windows 95 Release B can be upgraded to support USB (and AGP, Accelerated Graphics Port), and for many people its USB works fine, but Windows 98 has it all built in with no further fiddling required.

The USB card retails for $75 (Australian dollars).

Setting up

The Skymaster card comes with the cheesiest photocopied instruction sheet I've ever seen, which has the peculiar distinction of not even being right. The part about shutting down your computer and sticking the card into a spare USB slot is correct, but then it talks about getting a driver from a floppy disk in your A: drive. This is all very well for those with the ability to pull such a floppy disk out of a convenient bodily orifice, but since the USB card doesn't actually come with a driver disk, many people may find the instructions somewhat puzzling.

Fortunately, in Windows 98 at least, no driver disk is needed. Windows 98 has a driver included for USB cards using the same OPTi chipset as the Skymaster card. This chipset is used by various other USB cards, as well. Installation was, therefore, a painless process; pop in the card, start up the computer, click through the Add New Hardware wizard, presto.

I don't know whether the card will install this smoothly in Windows 95 Release B with the USB patch. The Dotop site has no 95 drivers for the card, so if it doesn't, you're on your own.

How it works

The result of all this, on my computer with its Asus P2B motherboard, which already has a USB controller, is another USB Root Hub, essentially the same as the existing one. The new USB Controller uses an IRQ and an I/O address range just like the standard one, and it works just the same, too. All of the standard USB features are supported - hot swapping, rebootless device installation, fast data transfer from devices that need it, easy further port expansion via cascadable hubs, and so on.

There's not much reason to install a USB card in a computer that's already got USB, since you can plug hubs into any existing USB controller and cascade them for as many ports as you want, up to the 127 device maximum that USB supports. I suppose that if you know for a fact that all you need is four ports, and you want to save a few bucks (the USB card is $AU40 cheaper than Skymaster's four port hub), and you've got a spare PCI slot, I/O range and IRQ, another USB controller would fit the bill. It also saves you from having a hub dangling from your computer, although bringing your USB ports up onto the desk with a hub reduces the back-of-computer cable snarl and therefore, I think, is much more of a plus than a minus. Adding a USB card to a USB-equipped computer takes you from two ports to four for $75; adding a hub takes you from two ports to five for $115.


A simple product, and it works. The instructions are dodgy, but the card works fine. If you want USB but your PC doesn't have it, here's an alternative to a whole new motherboard.


IRQ: Interrupt ReQuests are how IBM-compatible computers assign the CPU's attention to devices that need to talk to it right now. A device gets assigned a given IRQ and uses it whenever CPU time is required; if two devices have the same IRQ and try to use it at once, neither will work. Current PCs have 16 IRQ lines, but several of them are taken up by standard hardware. See my second Step By Step column for more information.

I/O address: I/O addresses, also referred to as "I/O ports" or "port addresses" are what a CPU uses to tell which of its peripherals is presently clamouring for its attention. If two devices are set to use the same I/O addresses, it's likely that neither will work. See my second Step By Step column for more information.

Give Dan some money!
(and no-one gets hurt)