HP (Hewlett-Packard) 7550e ユーザーズマニュアル

6. Attach the CD-Writer Plus drive’s  data cable to your computer’s 25-pin 

parallel port connector and hand tighten the retaining screws.

Attach the data cable’s remaining connector to the rewritable drive and 
secure it by tightening the retaining screws.      

CD-Writer Plus drive’s data cable

Attach this end to the CD-
Writer Plus drive.

Attach this end to the 
computer’s parallel port.