dp \- DP-11 201 data-phone interface
is a 201 data-phone interface.
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
The sync must be user supplied.
Each read call returns characters received from a
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.