1DZ(4) Kernel Interfaces Manual DZ(4)
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6 dz - DZ-11 communications multiplexer
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9 /sys/conf/SYSTEM:
10 NDZ dz_units # DZ11; NDZ is in units of boards (8 each)
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12 /etc/dtab:
13 #Name Unit# Addr Vector Br Handler(s) # Comments
14 dz ? 160100 310 5 dzrint dzdma # dz11 terminal mux
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16 major device number:
17 raw: 2
18 minor device encoding:
19 bits 0007 specify line on DZ unit
20 bits 0170 specify DZ unit
21 bit 0200 specifies non-blocking open (``CD always on'')
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24 A DZ11 provides 8 communication lines with partial modem control, ade‐
25 quate for UNIX dialup use. Each line attached to the DZ11 communica‐
26 tions multiplexer behaves as described in tty(4) and may be set to run
27 at any of 16 speeds; see tty(4) for the encoding.
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29 Bit 0200 of the minor device number for DZ lines may be set to say that
30 a line is not properly connected, and that the line should be treated
31 as hard-wired with carrier always present. Thus creating the special
32 character device node "2, 130" via mknod /dev/tty02 c 2 130 would cause
33 line tty02 to be treated in this way.
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35 The dz driver monitors the rate of input on each board, and switches
36 between the use of character-at-a-time interrupts and input silos.
37 While the silo is enabled during periods of high-speed input, the
38 driver polls for input 30 times per second.
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41 /dev/tty[0-9][0-9]
42 /dev/ttyd[0-9a-f] dialups
43 /dev/MAKEDEV script to create special files
44 /dev/MAKEDEV.local script to localize special files
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47 tty(4), dtab(5), autoconfig(8)
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50 dz%d: silo overflow. The 64 character input silo overflowed before it
51 could be serviced. This can happen if a hard error occurs when the CPU
52 is running with elevated priority, as the system will then print a mes‐
53 sage on the console with interrupts disabled. It is not serious.
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573rd Berkeley Distribution January 28, 1988 DZ(4)