xref: /netbsd-src/share/man/man4/man4.vax/dmf.4 (revision ce0bb6e8d2e560ecacbe865a848624f94498063b)
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32.\"     from: @(#)dmf.4	6.5 (Berkeley) 3/27/91
33.\"	$Id: dmf.4,v 1.2 1993/08/01 07:36:28 mycroft Exp $
34.\"
35.Dd March 27, 1991
36.Dt DMF 4 vax
37.Os BSD 4.2
38.Sh NAME
39.Nm dmf
40.Nd
41.Tn DMF-32
42terminal multiplexor
43.Sh SYNOPSIS
44.Cd "device dmf0 at uba? csr 0160340 vector dmfsrint dmfsxint dmfdaint dmfdbint dmfrint dmfxint dmflint"
45.Sh DESCRIPTION
46The
47.Nm dmf
48device provides 8 lines of asynchronous serial line support.
49The first two of these have full modem control.
50The device also provides a line printer port
51similar to the
52.Tn LP-11 .
53Other features of the
54.Tn DMF-32
55are not supported.
56During autoconfiguration, the driver examines the configuration of each
57.Tn DMF-32
58and adjusts the interrupt vectors so that fewer vector locations are used
59if possible.
60.Pp
61An optional argument
62.Ar flags
63may be supplied with the device specification
64in the config file indicating
65that the line corresponding to
66bit number
67.Ar i
68is not properly
69connected, and should be treated as hard-wired with carrier
70always present.  Thus specifying
71.Ql flags 0x04
72for
73.Li dmf0
74would cause line
75.Pa ttyA2
76to be treated in this way.
77Flags should be set for all lines without hardware support for modem control.
78.Pp
79Normal
80.Tn I/O
81control parameters for individual lines are managed by
82.Xr ioctl 2
83calls.
84Line speeds may be initiated via
85.Xr getty 8
86and
87.Xr stty 1
88or may be communicated by other programs which
89utilize
90.Xr ioctl
91such as
92.Xr ifcongif 8 ,
93see
94.Xr tty 4  .
95.Pp
96The serial line part of the
97.Nm dmf
98driver normally enables the input silos with a short timeout
99(30 milliseconds); this allows multiple characters to be received
100per interrupt during periods of high-speed input.
101.Pp
102A line printer port on a
103.Nm dmf
104is designated by
105a minor device number of the form
106.Pf 128+ Ns Ar n .
107See
108.Xr MAKEDEV 8 .
109Column and lines per page may be changed from the default
110132 columns and 66 lines by encoding the number of columns
111in bits 8-15 of flags and the number of lines in bits 16-23.
112This device does not provide the fancy output canonicalization
113features of the
114.Xr lp 4
115driver.
116.Sh FILES
117.Bl -tag -width "/dev/tty[A-CE-I][0-7]" -compact
118.It Pa /dev/tty[A-CE-I][0-7]
119.It Pa /dev/ttyd[0-7]
120.It Pa /dev/lp
121.El
122.Sh DIAGNOSTICS
123.Bl -diag
124.It dmf%d: NXM line %d.
125No response from
126.Tn UNIBUS
127on a DMA transfer
128within a timeout period.  This is often followed by a
129.Tn UNIBUS
130adapter
131error.  This occurs most frequently when the
132.Tn UNIBUS
133is heavily loaded
134and when devices which hog the bus (such as
135.Tn RK07 Ns s )
136are present.
137It is not serious.
138.Pp
139.It dmf%d: silo overflow.
140The character input silo overflowed
141before it could be serviced.  This can happen if a hard error occurs
142when the
143.Tn CPU
144is running with elevated priority, as the system will
145then print a message on the console with interrupts disabled.
146It is not serious.
147.Pp
148.It dmfsrint, dmfsxint, dmfdaint, dmfdbint.
149One of the unsupported parts of the dmf interrupted; something
150is amiss, check your interrupt vectors for a conflict with another
151device.
152.El
153.Sh SEE ALSO
154.Xr tty 4
155.Sh HISTORY
156The
157.Nm
158driver appeared in
159.Bx 4.2 .
160.Sh BUGS
161It should be possible to set the silo timeout with a configuration file option,
162as the value is a trade-off between efficiency and response time for flow
163control and character echo.
164