.\" Copyright (c) 1990 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" the Systems Programming Group of the University of Utah Computer
.\" Science Department.
.\"
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.\" that: (1) source distributions retain this entire copyright notice and
.\" comment, and (2) distributions including binaries display the following
.\" acknowledgement:  ``This product includes software developed by the
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.\" all advertising materials mentioning features or use of this software.
.\" Neither the name of the University nor the names of its contributors may
.\" be used to endorse or promote products derived from this software without
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.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
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.\"
.\"	@(#)dcl.4	5.1 (Berkeley) 6/29/90
.\"
.TH DCL 4 "June 29, 1990"
.UC 7
.SH NAME
dcl \- HP 98628A communications link
.SH SYNOPSIS
.B "device		dcl0	at scode? flags 0x1"
.SH DESCRIPTION
The 98628A is a buffered EIA RS-232C (CCITT V.28) communications interface.
It has one port with full modem control.
.PP
Each line attached to the 98628A behaves as described in
.IR tty (4).
Input and output for each line may set to one of following baud rates;
0, 50, 75, 110, 134.5, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
9600, 19200. See 
.IR tty (4)
for the encoding.
.PP
.I Flags
should be set to 1 if the line should be treated as hard-wired with
carrier always present, or to 0 if modem control is desired.
.PP
Use HP cable "98626 & 98628 opts.002, RS232-C DCE CABLE, 5061-4216" to attach non-modem devices.
Use HP cable "98626 & 98628 opts.001, RS232-C DTE CABLE, 5061-4215" to attach modems.
.PP
The 98628A has a 256 byte input silo and a 256 output silo. Input interrupts
happen on a per character basis.
.PP
The high water and low water marks in the kernel tty routines are totally
inappropriate for a device like this with a large input buffer.  Don't use
tandem mode if possible.  A fast system can handle input at 19.2K baud without
receive overflow.

For output to devices that make heavy use of XON/XOFF a write size of less
then 256 will improve performance marginally.
.SH FILES
/dev/ttyl[0-9]
.SH "SEE ALSO"
tty(4)
.SH DIAGNOSTICS
\fBdcl%d: error 0x%x RESET CARD\fR Where the errors are in coded as
.DS
0x06 card failure
0x0d uart receive overflow
0x0e receive overflow
0x0f missing external clock
0x10 cts false too long
0x11 lost carrier
0x12 activity timeout
0x13 connection not established
0x19 illegal databits/parity
0x1a register address out of range
0x1b register value out of range
0x-- unknown error
.DE
.SH BUGS
Breaks received at a faster rate then 1 break every second will be 
recognized as a single break.

Console use is not supported.

The RS-422/423/499, MTS-DSN/DL modes of the card are not supported.