Subject: Re: Working USB<->serial spotted in the wild!
To: Wolfgang Rupprecht <>
From: David Johnston <>
List: current-users
Date: 12/08/2001 11:43:28
On Fri, Dec 07, 2001 at 08:47:00AM -0800, Wolfgang Rupprecht wrote:
> (Peter Seebach) writes:
> > The local Micro Center carries (carried?) a USB/Serial converter made by
> > QVS, under the model number "USC-1000", or "USC-1009F", depending on which
> > label you believe.  It looks as though the "1009F" means it comes with a 25-9
> > pin adapter.
> One thing you may want to also try is ppp over this adaptor.  I spent
> quite a while trying to get ppp over a utty configured only to find
> out that the problems went away when I switched to a real tty/com
> port.
>     model: DSB-S25 
>     umct0: MCT Corporation. USB-232 Interfact Controller, rev 1.00/1.02, addr 4
> The symptoms were that the serial-line comms worked just fine, the PPP
> LCP packets were full duplex, but none of the IP from the remote side
> made it into the IP stack in the kernel.  Tcpdump showed outgoing
> packets, but only incoming LCP.  Weird.

I'm currently running PPP over my USB to serial adaptor. It works pretty
well, but not flawlessly. It'll run for a few days then something kills the
USB layer and I need to re-boot the machine to get anything USB working again.

I suspect this is a problem in the USB layer, or an interrupt problem in the
macppc kernel, as I see similar problems with other USB devices (a USB to
parallel port converter will similarly kill the USB layer after printing
a few files).


David Johnston
Email:	Mobile: 0402 088010