Simplify the following text for a Grade 9 native English-speaking person.
Original: Parallel port external Zip drives are actually SCSI drives with an integrated Parallel-to-SCSI controller , meaning a true SCSI bus implementation but without the electrical buffering circuits necessary for connecting other external devices .
Simplified: Internal drives have been made with IDE and SCSI interfaces . External drives can use SCSI , parallel port or USB interface .