Return to dh.4 CVS log

Up to [CSRG BSD Unix] / 43BSDTahoe / man / man4 / vax

Annotation of 43BSDTahoe/man/man4/vax/dh.4, revision 1.1

1.1     ! root        1: .\" Copyright (c) 1980 Regents of the University of California.
        !             2: .\" All rights reserved.  The Berkeley software License Agreement
        !             3: .\" specifies the terms and conditions for redistribution.
        !             4: .\"
        !             5: .\"    @(#)dh.4        6.2 (Berkeley) 5/16/86
        !             6: .\"
        !             7: .TH DH 4 "May 16, 1986"
        !             8: .UC 4
        !             9: .SH NAME
        !            10: dh \- DH-11/DM-11 communications multiplexer
        !            11: .SH SYNOPSIS
        !            12: .B "device dh0 at uba0 csr 0160020 vector dhrint dhxint"
        !            13: .br
        !            14: .B "device dm0 at uba0 csr 0170500 vector dmintr"
        !            15: .SH DESCRIPTION
        !            16: A dh-11 provides 16 communication lines; dm-11's may be optionally
        !            17: paired with dh-11's to provide modem control for the lines.
        !            18: .PP
        !            19: Each line attached to the DH-11 communications multiplexer
        !            20: behaves as described in
        !            21: .IR tty (4).
        !            22: Input and output for each line may independently
        !            23: be set to run at any of 16 speeds;
        !            24: see
        !            25: .IR tty (4)
        !            26: for the encoding.
        !            27: .PP
        !            28: Bit
        !            29: .I i
        !            30: of flags may be specified for a dh to say that a line is not properly
        !            31: connected, and that the line should be treated as hard-wired with carrier
        !            32: always present.  Thus specifying ``flags 0x0004'' in the specification of dh0
        !            33: would cause line ttyh2 to be treated in this way.
        !            34: .PP
        !            35: The
        !            36: .I dh
        !            37: driver monitors the rate of input on each board,
        !            38: and switches between the use of character-at-a-time interrupts
        !            39: and input silos.
        !            40: While the silo is enabled during periods of high-speed input,
        !            41: the driver polls for input 30 times per second.
        !            42: .SH FILES
        !            43: /dev/tty[h-o][0-9a-f]
        !            44: .br
        !            45: /dev/ttyd[0-9a-f]
        !            46: .SH "SEE ALSO"
        !            47: tty(4)
        !            48: .SH DIAGNOSTICS
        !            49: \fBdh%d: NXM\fR.  No response from UNIBUS on a dma transfer
        !            50: within a timeout period.  This is often followed by a UNIBUS adapter
        !            51: error.  This occurs most frequently when the UNIBUS is heavily loaded
        !            52: and when devices which hog the bus (such as rk07's) are present.
        !            53: It is not serious.
        !            54: .PP
        !            55: \fBdh%d: silo overflow\fR.  The character input silo overflowed
        !            56: before it could be serviced.  This can happen if a hard error occurs
        !            57: when the CPU is running with elevated priority, as the system will
        !            58: then print a message on the console with interrupts disabled.
        !            59: It is not serious.

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.