When I'm right, I'm right.

Seven months ago (NNN, Dec. 13) I cautioned readers that it was unclear whether the claims of new PCs to be "USB ready" were as meaningless as those of early "cable ready" tv sets. And not to rush to buy new equipment to capitalize on this exciting, but unproven technology.

USB stands for the widely hyped universal serial bus, an easier way of connecting computer peripheral devices (such as printers, scanners, modems, joysticks). If and when it works as advertised. Developed by Compaq, DEC, IBM, Intel, Microsoft, NEC, and Northern Telecom, the USB standard is intended to provide an intelligent serial bus for low- to mid-speed peripherals. A computer bus is the connecting path between the processor, memory and peripherals.

Windows 95 was touted as resolving connection headaches with its "plug and play" technology -- a good idea, poorly implemented, widely referred to as "plug and pray."

While most devices these days have done away with setting finicky, easily lost little jumpers, it remains all too common for users to have to fiddle with mysterious IRQs (interrupt requests), of which there is never a sufficient supply, to get equipment working. Clunky power supply boxes add to the rats-nest of electrical wires on and behind our desks. Attaching or removing a device requires shutting down the PC and demonstrating an agility with one's fingers best left to jugglers and magicians. USB should, and will someday soon, eliminate all that.

USB requires four components: a motherboard with a USB host controler; one or more USB connectors on the PC chassis; USB software drivers; and peripherals designed to plug into the USB connectors. Don't expect USB equipment to work unless all four parts of the equation are present.

Reports are now surfacing in trade journals (such as InfoWorld, June 15) that compatibility and/or hardware problems lurk for the unwary user. Many of the difficulties may be attributed to manufacturers releasing USB equipment before technology standards were set, in order to beat the competition to market. The USB specification theoretically permits up to 127 peripheral devices to be daisy-chained to a single host, but there are no devices actually available to accomplish this feat. One report suggests that a majority of devices purchased at retail and tested by a USB lab did not work, though they all appeared to the operating system as properly powered.

InfoWorld cites a source that indicates the possibility of cable fires from improperly designed or malfunctioning devices. Yet another source reports that a motherboard fuse was blown when a USB device was plugged in, perhaps permanently disabling that board from using USB devices. The fact is that there's no way to insure manufacturers' compliance with or conformity to USB design standards. The specification requires a connecting cable of five meters, and some experts say that serious consequences may result from longer or shorter cables.

There's no doubt that USB represents significant improvement in computer connectivity. There's also no reason for discouragement.

But non-technical users may wish to let someone else be the guinea pig until the bugs in the bus are tamed.

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