On Aug 2, 2011, at 12:24 AM, Xiaofan Chen wrote:

> MCP2200 used HID+CDC-ACM USB composite device. It is a good
> idea in a way since the HID side can be used for simple IO, like
> the  FTDI's D2xx. But then it will not work with Windows 2k

Sigh.  I've heard that MacOS also has problems with CDC-ACM endpoints =20
that are part of a composite device.  Here I was assuming that since =20
the microchip reference USB/Serial code worked on a Mac, the MCP2200 =20
would too.  Perhaps not.


> And in reality, CDC-ACM is really meant for modems.

In reality, rs232 is really meant for modems, too.
I had heard rather confusing reports that CDC as "communications =20
device" was getting pretty overloaded (serial, modem, ethernet...) and =20
was wondering how that was supposed to be working.  Sigh.
Does that mean that there isn't a USB standard for serial ports at =20
all?  How ... silly.

BillW

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