Apple Performa 6400/180 - Manual (Page 69)

Specifications I/O Interfaces - 15
Keyboard
Supports all Apple Desktop Bus (ADB) keyboards
Mouse
Supports all models of the ADB mouse
Controls
Infrared remote control option
Front-panel pushbutton controls for volume and picture
Softpower control from keyboard
SCSI
One external standard SCSI port that supports up to six external
SCSI devices (or up to five external SCSI devices if the optional
Zip drive is installed)
Serial Two RS-232/RS-422 serial GeoPort-compatible ports