Philips 170B4BB, Service Manual

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General Troubleshooting Guide (Continued)
USB
USB = Universal Serial Bus
USB is the simple way to connect peripherals to your computer. It can be used to attach a wide
variety of devices like scanners, cameras, keyboards, mice, speakers,printer ..etc.
Useing USB devices (Operating Systems support USB) :
It depends on two things: hardware and software.
Hardware : You need a USB port in your computer. This can either be built in (most PC's build in
1999 and Apple's iMac) or from a plug in card. A number of venders sell PCI and CardBus USB
adapters which can add USB capabilities to your older computer.
Software-wise for Wintel computers, you need either Windows 98, Windows 95 OSR 2.1
(although Windows 98 has better USB support than Windows 95), Windows 2000 . For Apple
Macintosh computers you need MacOS 8.1 or later .
USB automatically determines resources (like driver software and bus bandwidth)
required by peripherals.
USB makes necessary resources available without user intervention.
It is designed to meet Microsoft Plug and Play (PnP) specification, meaning users can install,
and hot-swap devices without long installation procedures and reboots.
It allows 127 devices to run at the same time on the bus.
USB bus provides two types of data transfer speed -- 1.5Mbps and 12Mbps
and it can provide a maximum of 500mA of current to devices attached on the bus.
Universal means all peripherals share the same connector.
Serial simply defines devices can daisy chain together.
Universal Serial Bus 1.1, the de facto external connectivity standard for Mac and PC,
has picked up the speed after its slow adoption by peripheral manufacturers, users and PC OEMs.
USB 2.0 :
Drafted by Compaq, Hewlett Packard, Intel, Lucent, Microsoft, NEC and Philips,
USB Specification version 2.0 will increase device data throughout
up to 480Mbps, 40 times faster than USB 1.1 devices.
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