ACC(4)                 OpenBSD Programmer's Manual (VAX)                ACC(4)

NAME
     acc - ACC LH/DH IMP interface

SYNOPSIS
     pseudo-device imp device acc0 at uba0 csr 167600 vector accrint accxint

DESCRIPTION
     The acc device provides a Local Host/Distant Host interface to an IMP. It
     is normally used when participating in the DARPA Internet.  The con-
     troller itself is not accessible to users, but instead provides the hard-
     ware support to the IMP interface described in imp(4). The configuration
     entry for the imp must also include the pseudo-device as shown above.

DIAGNOSTICS
     acc%d: not alive.  The initialization routine was entered even though the
     device did not autoconfigure.  This indicates a system problem.

     acc%d: can't initialize.  Insufficient UNIBUS resources existed to ini-
     tialize the device.  This is likely to occur when the device is run on a
     buffered data path on an 11/750 and other network interfaces are also
     configured to use buffered data paths, or when it is configured to use
     buffered data paths on an 11/730 (which has none).

     acc%d: imp doesn't respond, icsr=%b.  The driver attempted to initialize
     the device, but the IMP failed to respond after 500 tries.  Check the ca-
     bling.

     acc%d: stray xmit interrupt, csr=%b.  An interrupt occurred when no out-
     put had previously been started.

     acc%d: output error, ocsr=%b, icsr=%b.  The device indicated a problem
     sending data on output.

     acc%d: input error, csr=%b.  The device indicated a problem receiving da-
     ta on input.

     acc%d: bad length=%d.  An input operation resulted in a data transfer of
     less than 0 or more than 1008 bytes of data into memory (according to the
     word count register).  This should never happen as the maximum size of a
     host-IMP message is 1008 bytes.

SEE ALSO
     netintro(4)

HISTORY
     The acc interface appeared in 4.2BSD.

OpenBSD 3.0                     March 27, 1991                               1
