[OT] USB KVM switches

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Tue Feb 1 18:33:39 2005

> Ok, so what I don't understand is how USB became a successful and
> widespread standard if it's such a pile of shit. You and Tony,

Err, can you say 'Windows' :-)

> accomplished hardware designers both, think it's crap. It's great that

My main objection, other than the fact that nothing I have supports it or
can support it, is that it's typical of modern systems. It makes easy
jobs (hooking up a printer, mouse, modem, etc) trivial, but more
difficult jobs (homebrew interfacing) much more difficult. I can make
something that links to an RS232 or Centronics port from the bits in my
junkbox in about half an hour. I doubt I'd ever be able to do that with
USB...

In general I dislike the idea of 'one size fits all' solutions. There's
no good reason why a printer should use the same interface as a digital
camera or a keyboard or a mouse or.... TO try to fit everything into one
standard is likely to make things over-complex for no particularly good
reason.

Then there's fact it's a very 'assymetrical' interface. What I mean is
that given 3 devices with USB ports, it's not normally the case that you
can link any pair together (unlike RS232 given null-modem cables). You
have effecively 'master' devices like PCs and 'slave' devices like
printers, mice, etc.

Think of the HP49G+ calculator which has a USB port in place of the RS232
port of older models. That will link fine to a modern PC. But it won't
link directly to a printer. Or to a homebrew ADC interface. That's enough
to keep me from buying that calculator.

And to think that when HP made an HPIB interface availabel for their
calculators about 20 years ago (the 82169), it was by default a
controller (that is, the calcualtor was the master device on the HPIB),
but you could turn off the controller functions in software if you wanted
your calcualtor to just be a device on the HPIB. Back then HP did things
right...


-tony
Received on Tue Feb 01 2005 - 18:33:39 GMT

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