> If USB was meant to 'simplify' connectivity for slow speed
> devices, whey did they come out with USB 2.0?

USB does greatly simplify low speed device connections, if everybody sticks
to the spec. Marginal devices, cables, firmware and drivers that don't meet
the spec are what mess things up.

I believe USB 2.0 was a response to Firewire. I think there was fear that
Firewire would gobble up the low speed as well as high speed market. Also,
there are some applicaitons, like cameras and scanners, that can really use
a little bit more than the 12MBit from the original USB.

> And why do I have to add a separate and distinct 'device driver'
> for EVERY new device, unlike RS232 or firewire, where the
> application talks to ONE STANDARDIZED API?

You don't. You need a device driver for every device class for standard
classes like HID devices and mass storage.

One advantage of USB over RS232 is that it allows more versatile control of
the shared medium. You can have isochronous transfers handing sound, bulk
transfers moving data around, and control/interrupt transfers handling HID
devices all at the same time, and nobody can stomp on each-others
timeslot/bandwidth.

> And if one has used a few dozen different devices over time,
> one is stuck with ALL those drivers being loaded by Winblows,
> even if the device is now in the dumpster.

Feel free to go into the device manager and poof 'em.

> Oh, right, Firewire (tm) was doing too well in the marketplace
> they needed to add some confusion.
> But if you've ever tried USB 2.0, you'll discover it is nearly *useless*
> for *multiple* high speed streams, unlike Firewire(tm) AKA IEEE 1394.

But how often do you need *multiple* high speed streams. And, btw, why do
you say that USB 2.0 can't handle multiple high speed streams.

> And of course USB works every time, and is EASY to implement
> on embedded processors like the PIC (NOT!).

Yeah, just like firewire.

> There is much good to be said for 'legacy ports'
> (serial and parallel). They WORK! and are easy
> to connect to simple PIC hardware.

Well, I can agree with that. At least.

> Robert

Bob Ammerman
RAm Systems

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