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
NetBSD
1.3.
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.