Date   : Sun, 01 Sep 1985 09:57:00 MDT
From   : Keith Petersen <W8SDZ@SIMTEL20.ARPA>
Subject: X.PC protocol description available

Now available via anonymous FTP from SIMTEL20:

       Filename                Type     Bytes   CRC

Directory MICRO:<CPM.MODEM>
       X-PC.DOC.1              ASCII   127850  34DFH
       X-PC.DQC.2              BINARY   77056  CA2CH <-same, squeezed

[Keith: which MAY be the same as TYMNET offers as:]

Now available from your local Tymnet sales representative:

X.PC PROTOCOL SPECIFICATIONS                    NPD-269     $3.00    

This specification is published by McDonnell Douglas as a proposal to
designers and implementors of personal computer communications
software and packet network systems.

It defines the formats and procedures at X.PC's packet and data line
layers for Data Terminal Equipment (DTE) and Data Communications
Equipment (DCE).  Both switched virtual call and permanent virtualy
call modes of operation are defined.

This specification covers DTE and DCE operation when a packet switched
network is accessed through a circuit switched or dedicated
connection.  It also includes the additional packet layer procedures
necessary for two DTEs to communicate directly (i.e., without an
intervening packet switched network) over dedicated or circuit
switched connection.

[Keith: this is the much-talked-about "error-free terminal protocol"
now supported by TYMNET.  It is an interesting alternative to
MICROCOM's "MNP" protocol which you must buy a new modem to get (and
which requires the "other end" to also have this type modem).  If we
could get BBN to support the X.PC protocol in the TAC software, we
could have error-free sessions in spite of occasional noise on the
phone lines.]

--Keith