NAME
dz —
DZ-11 serial multiplexer device
interface
SYNOPSIS
dz0 at uba0 csr 0160100 vector dzrint dzxint
DESCRIPTION
A DZ-11 provides 8 communication lines with partial modem control, adequate for
UNIX 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 hard-wired 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,
stty(1) or
ifconfig(8) to name a few,
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
- /dev/tty[0-9][0-9]
-
- /dev/ttyd[0-9a-f]
- dialups
DIAGNOSTICS
- 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
stty(1),
tty(4),
ttys(5),
getty(8)
HISTORY
A
dz driver appeared in
Version 32V
AT&T UNIX.