DL(4)                 NetBSD/vax Kernel Interfaces Manual                DL(4)

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.

NetBSD 5.0_STABLE              January 28, 1997              NetBSD 5.0_STABLE
