Visit Our UNIX and Linux User Community

Linux and UNIX Man Pages

Test Your Knowledge in Computers #554
Difficulty: Medium
Using printf() in C, %d formats a decimal variable or literal.
True or False?
Linux & Unix Commands - Search Man Pages

dr(4) [bsd man page]

DR(4)							     Kernel Interfaces Manual							     DR(4)

dr - DR11-W general purpose interface driver SYNOPSIS
/sys/conf/SYSTEM: NDR dr11-w_units # DR11-W /etc/dtab: #Name Unit# Addr Vector Br Handler(s) # Comments dr ? 172410 124 5 drintr # dr11-w (b-bus emulator) dr ? 172430 130 5 drintr # dr11-w (gc-bus emulator) dr ? 172450 134 5 drintr # dr11-w (em-2 interface) major device number(s): raw: 12 minor device encoding: bits 0007 specify DR unit DESCRIPTION
The Digital Equipment 1981-82 Peripherals Handbook states the following about the DR11-W: The The DR11-W is a general purpose, direct memory access (DMA) interface to the PDP-11 UNIBUS or VAX UNIBUS. The DR11-W moves data directly between memory and the UNIBUS to and from the user's peripheral. It features: o Word or byte transfers. o Programmed or direct memory access (DMA) block transfers. o Burst data transfers. o User-controlled transfer rates up to memory speed. The DR11-W is a 53-line direct memory access (DMA) interface to the PDP-11 UNIBUS or VAX UBA, which allows the user to control data transfers between the host processor and a peripheral. The DR11-W has 32 data lines (for transferring 16-bit parallel data) and 21 control lines (for transferring control and status information. When used as an interprocessor buffer (IPB), the DR11-W allows data transfers between two processors. Interprocessor communication is accomplished by attaching one DR11-W to each processor UNIBUS or UBA and then cabling the two DR11-Ws together. There. Now you know as much about it as I do. A number of ioctl(2) calls apply to the dr devices, and have the form #include <pdpuba/drreg.h> ioctl(fildes, code, arg) int *arg; The applicable codes are: DRGTTY Get DR11-W status. DRSTTY Set flags and function. DRSFUN Set function. DRSFLAG Set flags. DRGCSR Get CSR and WCR. DRSSIG Set signal for ATTN interrupt. DRESET Reset DR11-W interface. DRSTIME Set timeout. DRCTIME Set timeout inactive. DROUTPUT Put word in output data register. DRINPUT Get word from input data register. DRITIME Don't ignore errors on timeout. FILES
/dev/dr[0-7] device special files /dev/MAKEDEV script to create special files /dev/MAKEDEV.local script to localize special files SEE ALSO
dtab(5), autoconfig(8) DIAGNOSTICS
dr%d: error csr=%b, eir=%b dr%d: timeout error BUGS
This interface is only available under 2.9BSD and 2.11BSD. No documentation exists on how to use it. 3rd Berkeley Distribution January 27, 1996 DR(4)

Check Out this Related 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)

Featured Tech Videos