This article is from the Programming VCOMM FAQ, by firstname.lastname@example.org (Taed Nelson) with numerous contributions by others.
Microsoft Developer Network Device Driver Kit (MSDN DDK), July 1996.
"Communications Device Drivers" (\DDK\Docs\Desguide\Comm.doc), also known as
the Vcomm documentation. In addition to the change of file name, this
document changed significantly on the April 1996 DDK. (A copy of this file,
but not necessarily the newest, can also be obtain by sending a message body
of "get vcomm comm.doc.uu" to email@example.com.)
Serial.vxd Source Code (\DDK\Comm\Samples\Serial\*.*). This is (or seems to
be) the source code for the Serial.vxd port driver.
Microsoft Developer Network Software Development Kit (MSDN SDK), January 1996.