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dh(4) [bsd man page]

DH(4)							     Kernel Interfaces Manual							     DH(4)

dh - DH-11/DM-11 communications multiplexer SYNOPSIS
/sys/conf/SYSTEM: NDH dh_units # DH11; NDH is in units of boards (16 each) NDM dm_units # DM11; NDM is in units of boards (16 each) /etc/dtab: #Name Unit# Addr Vector Br Handler(s) # Comments dm ? 170500 310 4 dmintr # dm11 dh modem control dh ? 160020 320 5 dhrint dhxint # dh11 terminal mux major device number(s): raw: 3 minor device encoding: bits 0017 specify line on DH unit bits 0060 specify DH unit bit 0100 specify RTS/CTS (``hardware'') flowcontrol bit 0200 specifies non-blocking open (``CD always on'') DESCRIPTION
A dh-11 provides 16 communication lines; dm-11's may be optionally paired with dh-11's to provide modem control for the lines. If there are fewer dm-11's than dh-11's, the dm-11's are assumed to be paired with the first dm_units dh-11's. Each line attached to the DH-11 communications multiplexer behaves as described in tty(4). Input and output for each line may indepen- dently be set to run at any of 16 speeds; see tty(4) for the encoding. Bit 0200 of the minor device number for DH 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 "3, 130" via mknod /dev/ttyh2 c 3 130 would cause line ttyh2 to be treated in this way. Bit 0100 of the minor device number enables RTS/CTS (also called ``hardware'') flow con- trol. It is enabled by adding 64 to the minor device number: mknod /dev/ttyh2 c 3 194 The dh 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[h-k][0-9a-f] /dev/ttyd[0-9a-f] /dev/MAKEDEV script to create special files /dev/MAKEDEV.local script to localize special files SEE ALSO
tty(4), dtab(5), autoconfig(8) DIAGNOSTICS
dh%d NXM. No response from UNIBUS on a dma transfer within a timeout period. This has never been observed on a PDP-11 and is a carryover from the VAX driver when it was ported. It is not serious. dh%d %d overruns. The character input silo overflowed before it could be serviced. This message is only printed at line close time. It is not serious but does indicate that the system was not able to keep up with the data flow. 3rd Berkeley Distribution May 31, 1997 DH(4)

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TM(4)							     Kernel Interfaces Manual							     TM(4)

tm - TM-11/TE-10 magtape interface SYNOPSIS
/sys/conf/SYSTEM: # Setting AVIVTM configures the TM driver for the AVIV 800/1600/6250 # controller. For more details, see /sys/pdpuba/tm.c. NTM tm_drives # TM11 AVIVTM YES # AVIV 800/1600/6250 controller /etc/dtab: #Name Unit# Addr Vector Br Handler(s) # Comments tm ? 172520 224 5 tmintr # tm11 driver major device number(s): raw: 7 block: 1 minor device encoding: bits 0003 specify TS drive bit 0004 specifies no-rewind operation bits 0030 specify recording density: 0000: 800BPI 0010: 1600BPI (AVIVTM and some other controllers) 0020: 6250BPI (AVIVTM only) DESCRIPTION
The tm-11/te-10 combination provides a standard tape drive interface as described in mtio(4). The standard DEC tm-11 operates only at 800 bpi. Other controllers of this type may also allow operation at 1600 bpi, under software control or by switching manually. 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), ht(4), ts(4), mt(4), dtab(5), autoconfig(8) DIAGNOSTICS
te%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. te%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. te%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. te%d: hard error bn%d er=%b. A tape error occurred at block bn; the tm error register is 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. te%d: lost interrupt. A tape operation did not complete within a reasonable time, most likely because the tape was taken off-line during rewind or lost vacuum. The controller should, but does not, give an interrupt in these cases. The device will be made available again after this message, but any current open reference to the device will return an error as the operation in progress aborts. BUGS
If any non-data error is encountered on non-raw tape, it refuses to do anything more until closed. 3rd Berkeley Distribution January 28, 1988 TM(4)

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