dzq(4)dzq(4)Namedzq - DZQ11 communications interface
device dz0 at uba0 csr 0160100 flags 0x????
vector dzrint dzxint
A DZQ11 provides four communication lines with partial modem control,
adequate for dialup use. Each line attached to the DZQ11 communica‐
tions interface behaves as described in and can be set to run at any of
16 speeds. See for the encoding.
Bit i of can be specified for a to say that a line is not properly con‐
nected, and that the line should be treated as hardwired, with carrier
always present. Thus, specifying ``flags 0x04'' in the specification
of would cause line 2 to be treated in this way.
The driver normally uses its input silos and polls for input at each
clock tick (10 milliseconds), rather than taking an interrupt on each
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 then prints a message on the console
with interrupts disabled.
(modem lines only)
See Alsotty(4), MAKEDEV(8)