From: todd <markleyt@compusleuth.com>

>DEC never used DTR for flow 
>control, but it did use Xon/Xoff.

There's always an exception:  the DEC PDT-11/150 used DTR flow control on
most of its serial ports (I think the modem port was more vanilla though).
But yeah when DEC wasn't being crazy, they used XON/XOFF, so data-leads-only
cables almost always work (except on modems).

John Wilson
D Bit