dz(4) [bsd man page]
DZ(4) Kernel Interfaces Manual DZ(4) NAME
dz - DZ-11 communications multiplexer SYNOPSIS
/sys/conf/SYSTEM: NDZ dz_units # DZ11; NDZ is in units of boards (8 each) /etc/dtab: #Name Unit# Addr Vector Br Handler(s) # Comments dz ? 160100 310 5 dzrint dzdma # dz11 terminal mux major device number: raw: 2 minor device encoding: bits 0007 specify line on DZ unit bits 0170 specify DZ unit bit 0200 specifies non-blocking open (``CD always on'') DESCRIPTION
A DZ11 provides 8 communication lines with partial modem control, adequate for UNIX dialup use. Each line attached to the DZ11 communica- tions multiplexer behaves as described in tty(4) and may be set to run at any of 16 speeds; see tty(4) for the encoding. Bit 0200 of the minor device number for DZ lines may be set to say that a line is not properly connected, and that the line should be treated as hard-wired with carrier always present. Thus creating the special character device node "2, 130" via mknod /dev/tty02 c 2 130 would cause line tty02 to be treated in this way. 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 /dev/MAKEDEV script to create special files /dev/MAKEDEV.local script to localize special files SEE ALSO
tty(4), dtab(5), autoconfig(8) 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. 3rd Berkeley Distribution January 28, 1988 DZ(4)
Check Out this Related Man Page
HT(4) Kernel Interfaces Manual HT(4) NAME
ht - TM-03/TE-16,TU-45,TU-77 MASSBUS magtape interface SYNOPSIS
/sys/conf/SYSTEM: NHT ht_drives # TE16, TU45, TU77 /etc/dtab: #Name Unit# Addr Vector Br Handler(s) # Comments ht ? 172440 224 5 htintr # tu 16 massbus tape major device number(s): raw: 6 block: 0 minor device encoding: bits 0003 specify HT drive bit 0004 specifies no-rewind operation bit 0010 specifies 1600BPI recording density instead of 800BPI DESCRIPTION
The tm-03/transport combination provides a standard tape drive interface as described in mtio(4). All drives provide both 800 and 1600 bpi; the TE-16 runs at 45 ips, the TU-45 at 75 ips, while the TU-77 runs at 125 ips and autoloads tapes. FILES
/dev/MAKEDEV script to create special files /dev/MAKEDEV.local script to localize special files SEE ALSO
mt(1), tar(1), tp(1), mtio(4), tm(4), ts(4), dtab(5), autoconfig(8) DIAGNOSTICS
tu%d: no write ring. An attempt was made to write on the tape drive when no write ring was present; this message is written on the termi- nal of the user who tried to access the tape. tu%d: not online. An attempt was made to access the tape while it was offline; this message is written on the terminal of the user who tried to access the tape. tu%d: can't change density in mid-tape. An attempt was made to write on a tape at a different density than is already recorded on the tape. This message is written on the terminal of the user who tried to switch the density. tu%d: hard error bn%d er=%b ds=%b. A tape error occurred at block bn; the ht error register and drive status register are printed in octal with the bits symbolically decoded. Any error is fatal on non-raw tape; when possible the driver will have retried the operation which failed several times before reporting the error. BUGS
If any non-data error is encountered on non-raw tape, it refuses to do anything more until closed. The system should remember which controlling terminal has the tape drive open and write error messages to that terminal rather than on the console. 3rd Berkeley Distribution January 28, 1988 HT(4)