NAME    [Toc]    [Back]

     dz - DZ-11 multiplexer device interface

SYNOPSIS    [Toc]    [Back]

     dz0 at uba0 csr 0160100
     dz0 at vsbus0 csr 0x200a0000 (DC-367)
     dz0 at vsbus0 csr 0x25000000 (VS4000/90 4000/10x MV3100/9x)

DESCRIPTION    [Toc]    [Back]

     A DZ-11 provides 4 or 8 communication lines with partial modem control,
     adequate for OpenBSD dialup use.

     An  optional  argument flags may be supplied with the device
specification
     in the config file indicating that the line corresponding to
bit number i
     is  not  properly  connected, and should be treated as hardwired with carrier
 always present.  Thus specifying `flags 0x04'  for  dz0
would cause
     line tty02 to be treated in this way.

     Normal  I/O control parameters for individual lines are managed by
     ioctl(2) calls.   Line  speeds  may  be  initiated  via  the
ttys(5) file or
     stty(1), see tty(4).

     The  dz driver monitors the rate of input on each board, and
switches between
 the use of character-at-a-time  interrupts  and  input
silos.  While
     the  silo is enabled during periods of high-speed input, the
driver polls
     for input 30 times per second.

FILES    [Toc]    [Back]

     /dev/tty[0-9][0-9]    dialups

DIAGNOSTICS    [Toc]    [Back]

     dz%d: silo overflow.  The 64 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.

SEE ALSO    [Toc]    [Back]

     intro(4), tty(4), uba(4), vsbus(4)

HISTORY    [Toc]    [Back]

     A dz driver appeared in Version 32V AT&T UNIX.

OpenBSD     3.6                          March      27,      1991