4.3BSD-UWisc/man/cat4/dmf.4

DMF(4)              UNIX Programmer's Manual               DMF(4)



NAME
     dmf - DMF-32, terminal multiplexor

SYNOPSIS
     device dmf0 at uba? csr 0160340
          vector dmfsrint dmfsxint dmfdaint dmfdbint dmfrint
     dmfxint dmflint

DESCRIPTION
     The _d_m_f device provides 8 lines of asynchronous serial line
     support.  The first two of these have full modem control.
     The device also provides a line printer port similar to the
     LP-11.  Other features of the DMF-32 are not supported.
     During autoconfiguration, the driver examines the configura-
     tion of each DMF-32 and adjusts the interrupt vectors so
     that fewer vector locations are used if possible.

     Each line attached to a DMF-32 serial line port behaves as
     described in _t_t_y(4).  Input and output for each line may
     independently be set to run at any of 16 speeds; see _t_t_y(4)
     for the encoding.

     Bit _i of flags may be specified for a _d_m_f to to say that a
     line is not properly connected, and that the line should be
     treated as hard-wired with carrier always present.  Thus
     specifying ``flags 0x04'' in the specification of _d_m_f0 would
     cause line ttyA2 to be treated in this way.  Flags should be
     set for all lines without hardware support for modem con-
     trol.

     The serial line part of the _d_m_f driver normally enables the
     input silos with a short timeout (30 milliseconds); this
     allows multiple characters to be received per interrupt dur-
     ing periods of high-speed input.

     A line printer port on _d_m_f_n is designated by a minor device
     number of the form 128+_n.  Columns and lines per page may be
     changed from the default 132 columns and 66 lines by encod-
     ing the number of columns in bits 8-15 of flags and the
     number of lines in bits 16-23.  This device does not provide
     the fancy output canonicalization features of the _l_p(4)
     driver.

FILES
     /dev/tty[A-CE-I][0-7]
     /dev/ttyd[0-7]
     /dev/lp

SEE ALSO
     tty(4)





Printed 12/27/86          May 16, 1986                          1






DMF(4)              UNIX Programmer's Manual               DMF(4)



DIAGNOSTICS
     dmf%d: NXM line %d.  No response from UNIBUS on a DMA
     transfer within a timeout period.  This is often followed by
     a UNIBUS adapter error.  This occurs most frequently when
     the UNIBUS is heavily loaded and when devices which hog the
     bus (such as RK07s) are present.  It is not serious.

     dmf%d: silo overflow.  The character input silo overflowed
     before it could be serviced.  This can happen if a hard
     error occurs when the CPU is running with elevated priority,
     as the system will then print a message on the console with
     interrupts disabled.  It is not serious.

     dmfsrint, dmfsxint, dmfdaint, dmfdbint.  One of the unsup-
     ported parts of the dmf interrupted; something is amiss,
     check your interrupt vectors for a conflict with another
     device.

BUGS
     It should be possible to set the silo timeout with a confi-
     guration file option, as the value is a trade-off between
     efficiency and response time for flow control and character
     echo.
































Printed 12/27/86          May 16, 1986                          2