ACC(4)

NAME
acc - ACC LH/DH IMP interface

SYNOPSIS
/sys/conf/SYSTEM:
	NACC	0	# ACC LH/DH ARPAnet IMP interface
	PLI	YES	# LH/DH is connected to a PLI

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 controller itself is not accessible to users, but instead provides the hardware support to the IMP interface described in imp(4). When configuring, the imp(NIMP) pseudo-device must also be included.

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 initialize 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 cabling.

acc%d: stray xmit interrupt, csr=%b. An interrupt occurred when no output 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.