ACC(4) BSD/vax Kernel Interfaces Manual ACC(4)NAMEacc — ACC LH/DH IMP interface
pseudo-device imp device acc0 at uba0 csr 167600 vector accrint accxint
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.
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
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
data 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.
The acc interface appeared in 4.2BSD.
4.2 Berkeley Distribution June 5, 1993 4.2 Berkeley Distribution