The Mudcat Café TM
Thread #59388 Message #948988
Posted By: JohnInKansas
08-May-03 - 07:24 PM
Thread Name: BS: Spam and Porn - how to get rid of it?
Subject: RE: BS: Spam and Porn - how to get rid of it?
Some of the "consumer grade" newer machines do come with several USB connectors all tied to the same port. You can safely plug only one device in, although you can use any of the connectors for that one device.
Better machines actually have a built-in "USB Hub" so that you can use any or all of the connectors for different devices at the same time.
One of the main purposes of the USB connection is that it is designed to accept inputs from more than one device, but there has to be an appropriate "daisy chain" of the devices so that the bus can tell which device sent each signal, and tell the proper device that "this signal is yours" when it sends something back.
The setup is somewhat similar to the older (but still very good) SCSI connection. (SCSI = Small Computer System Interface, pronounced "skuzzy") In a SCSI system, the first device is connected to the "controller" and a "terminator" is placed on the other end of the first device. The "terminator" tells the controller "ain't nothin' more there, don't go any farther."
To add a second SCSI device, you plug the second one into the first one - and move the "terminator" to the other end of the second one.
USB is somewhat similar, in that things need to be connected in a way that lets the individual devices be identified by the USB controller. For a simple "plug two things into one socket" setup, you can use a "splitter," which often just looks like a piece of cable. One end plugs into the computer, and the other end has two sockets where you can plug in two separate devices. It may actually have a little "box" on the end, but the function is the same.
A "splitter" may have "primary" and "secondary" sockets, and you may have to use the "primary" before the "secondary" works. This is not the way it's supposed to be, but can happen if the splitter mfr cut some corners. If the PC mfr cut the same corners and used a poorly implemented "splitter" for a half-dozen USB connectors on your box, I suppose you can console yourself that he probably saved a few bucks - and of course passed the savings on to you...(?)
For more complex connections, more than 2 or 3 devices on a single USB controller, you probably need a true "USB HUB," and a decent machine with multiple USB connectors should have a hub built in. You can also get external hubs, typically connecting up to 4 or 8 devices to one USB connector on the machine.
It should be noted that if your machine has a built in hub adding an external hub can cause "LAN Looping" that can seriously degrade performance of your whole machine. (A multi-device USB setup with a hub is a "Local Area Network" to your machine). Win2K or WinXP will set things up automatically, usually with no problems, but it may add a couple of unexpected "protocols" on your machine. I don't have any information on WinME, but it should work about like XP(?). Earlier Windows versions can have problems with multi-hub setup, but they are not common.
There is a newer (than USB-2) standard that's supposedly even faster, but hardware is still rather rare for it. The main use for new the "super USB" would be in a really sophisticated DVD display setup.