NAME
dl
-
DL-11/DLV-11
serial device driver
SYNOPSIS
dl0 at uba? csr 0176500
dl1 at uba? csr 0176510
dl2 at uba? csr 0176520
dl3 at uba? csr 0176530
DESCRIPTION
The
dl
driver controls a
DL-11-compatible
asynchronous serial card, and probably things compatible with it. A
four-port
DLV-11J
will appear four times in the device list, as the ports look like
separate cards to the driver.
The
dl
driver provides the normal interface described in
tty(4),
but many of the configuration calls are unsupported, since their
functions are handled by jumpers or switches on the serial card
itself. Calls related to modem-control lines are also ignored, since
these cards lack them.
There's a chance this driver might also work with an
LP11,
an
LPV11
or even a
PC11,
but it hasn't been tested.
FILES
/dev/ttyJ?
-
Special files for communicating with dl devices.
DIAGNOSTICS
- dl%d: rx overrun.
-
The character in the receive buffer wasn't read before the next
character arrived, and has been lost.
- dl%d: stray rx interrupt.
-
The driver was called to service a receive interrupt, but there was
nothing for it to read.
SEE ALSO
tty(4)
HISTORY
The
dl
driver was written for
NetBSD1.3.
AUTHORS
Ben Harris <bjh21@NetBSD.org>
BUGS
The
DL-11
and friends only have single-character receive and transmit buffers,
so an interrupt is generated for every character received or
transmitted. Attempting to receive data at even moderately high rates
will cause rx overruns. Fast transmission seems to be fine though.
There is no support in the driver for the paper-tape reader on an
LT33
attached via a
DLV-11KA
or similar.
The overrun message is logged in the interrupt routine itself, which
will probably just make the problem worse.
The CSR printed on startup is that of the receiver, while the
interrupt vector is that of the transmitter.
In order to determine the card's interrupt vector, the driver sends a
NUL
to each port. This may confuse things attached to them.
The driver has so far only been tested on a
DLV-11J.
It may or may not work on the other cards it claims to support.