CSS(4)                                                                  CSS(4)



NAME
       css - DEC IMP-11A LH/DH IMP interface

SYNOPSIS
       pseudo-device imp
       device css0 at uba0 csr 167600 flags 10 vector cssrint cssxint

DESCRIPTION
       The  _c_s_s 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
       hardware support to the IMP interface described in _i_m_p(4).   When  con‐
       figuring, the _i_m_p pseudo-device is also included.

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

       css%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).

       css%d:  imp doesn’’t respond, icsr=%b.  The driver attempted to initial‐
       ize the device, but the IMP failed to respond after 500  tries.   Check
       the cabling.

       css%d:  stray  output  interrupt csr=%b.  An interrupt occurred when no
       output had previously been started.

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

       css%d:  recv  error,  csr=%b.  The device indicated a problem receiving
       data on input.

       css%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.



4.2 Berkeley Distribution        May 15, 1985                           CSS(4)