NAME

du, dp − DU-11 201 data-phone interface

DESCRIPTION

The dp0 file is a 201 data-phone interface.  Read and write calls to dp0 are limited to a maximum of 512 bytes.  Each write call is sent as a single record.  Seven bits from each byte are written along with an eighth odd parity bit.  The sync must be user supplied.  Each read call returns characters received from a single record.  Seven bits are returned unaltered; the eighth bit is set if the byte was not received in odd parity.  A 10 second time out is set and a zero-byte record is returned if nothing is received in that time. 

The unibus interrupt request priority level for the DU-11 must be set to BR 6. 

FILES

/dev/dp0
/dev/du#

SEE ALSO

dn(4)
ULTRIX-11 System Management Guide, Section 2.6 and Appendix A
ULTRIX-11 Software Technical Description

RESTRICTIONS

The DU-11 is obsolete and is not supported by ULTRIX-11. 
The name dp0 is a historical dreg.