Dale,
USB is a generic standard, and it allows two basic modes of operation: low
speed and high speed. This is for the USB 1.x standard. USB 2.0 is the
latest standard, and has a higher speed again. I beleive the HP product is
using the "high speed" of the 1.x standard. This would be 12 Mb/s. The
"low" speed of USB is 1.5 Mb/s, and the USB 2.0 higher speed is 480 Mb/s.
The low speed is really intended for really low volume devices such as
keyboards, mice and other things that need very small amounts of data
transferred per packet. (Childrens toys that connect via USB would most
likely also fall into this category).
The high speed is for scanners, printers, web-cams, USB speakers(stupid
things!) and such devices...
The USB 2.0 speed is intended for data access to really high performance
devices, for example portable storages such as hard disks, DVD players, CD
or DVD burners and so on. I'm sure the latest versions of high performance
scanners will also use USB 2.0 (but probably only small portion of the
bandwidth).
Most computers today will have USB 1.X built in, but only the really high
end ones will come with USB 2.0 built in. However, all of the USB standards
as they stand today are compatible with each other, so you can plug a 2.0
device into a 1.0 socket, and it will fall back to 1.0 speed (naturally,
trying to burn a CD with this may not work if the CD burner doesn't have
large enough buffers!).
Some of the early USB capable chipsets in some (now quite old) PC's have
problems with communication, especially with Windows 98 that has some bugs
of it's own in the USB section. If you do have problems with the USB port,
one solution is to buy a USB 2.0 card that plugs into the PCI slot of your
PC. This will come with it's own drivers that hopefully works in your
system... ;-) But before you do that, try the fixes that Microsoft has to
offer on their web-site.
Hope this helps.
--
Mats Petersson
At 02:21 PM 1/15/2003, you wrote:
>What if a film scanner says it is designed for high speed USB ports. Does
>that mean it will work with my lower speed ones but only slower? If so how
>much slower? Thanks for the help. Dale
>
>Reference:
>
>Hewlett Packard PhotoSmart Film Scanner
>Versatile scanner handles film, prints, or slides
> * Affordable "personal" film scanner
>* 2400 dpi resolution (24 meg file from 35mm neg!)
>* Slides, negatives, or prints up to 5x7 in one unit
>* High-speed USB interface (no card needed!)
>* Full 36-bit scanning, exceptional color accuracy!
>
>---
>$ dale-reed@att.net Seattle, Washington USA $
>
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