DR(4) Kernel Interfaces Manual DR(4)
dr - DR11-W general purpose interface driver
NDR dr11-w_units # DR11-W
#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):
minor device encoding:
bits 0007 specify DR unit
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.
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
ioctl(fildes, code, 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.
/dev/dr[0-7] device special files
/dev/MAKEDEV script to create special files
/dev/MAKEDEV.local script to localize special files
dr%d: error csr=%b, eir=%b
dr%d: timeout error
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)