Re: ugen vs interfaces

[Mouse <mouse%Rodents-Montreal.ORG@localhost>]

> [apologies in advance, I'm using Outlook which really is annoying for
> plain text/list responses.  Let me know if I should have hard-wrapped
> the line-endings, I forget the convention.]

It looks fine to me.

>> So the "intf 1 ep 0" endpoint is actually the same thing as the
>> "intf 2 ep 1" endpoint, because they're both address 2, even though
>> one is UE_DIR_IN and the other is UE_DIR_OUT?
> The bEndpointAddress 0x82 is not the same as 0x02 -- at least to the
> hardware on your device.

So when I open /dev/ugen1.02 and read, it uses 0x82, but if I write, it
uses 0x02?  Or at least it should?  Because there is no /dev/ugen1.130
or any such - nor does the minor-number cracking code in the driver
show anything of the sort.

>> Perhaps it would also help to ask "what's an interface"?  They seem
>> to be at the heart of my confusion here....

> An interface is primarily an abstraction of interest to software on
> the host.

> An 'interface' represents: [...]

Ooo.  So an interface is not actually visible on the wire, except in
the form of the device saying "here, put these fragments together and
they collectively form a conceptual thing" when queried?  Things make a
bit more sense to me now.

> [...]
> More than you wanted to know, I'm sure.

No, this is actually very helpful.  It's much easier to make sense out
of things like ugen(4) when I actually have some clue what the concepts
they're talking about are.  (Reference documentation tends ot be like
that.)

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