Pitch bend does not center correctly on the SN76489

[wik-wav]

After adding a midi automation lane and sending any pitch bend change in a DAW (and I presume moving the pitch wheel would cause this as well, but I can't test this as I have no controller) the pitch of the SN76489 moves down by half of the total pitch bend range. In DAWs where there is always a midi lane, the pitch is wrong from the start. This happens on midi channels 2 and 4.

For example if the note C is played, the note 2 semitones below it is A#. Before adding the pitch bend automation the note C is played. After adding PB, the note A# is played with the pitchbend at 0.