All Network Servers feature an internal two-channel Wide SCSI-2 controller (narrow, to the CD-ROM drive, and to any hard drives which have been installed with the Apple accessory Narrow SCSI-2 installation kit), an external 25-pin SCSI-1 connector and a standard 1.44 MB "SuperDrive" floppy. Six free PCI slots are available for expansion—parts supported under AIX include two Ethernet cards and a SCSI RAID card. Other ports include one ADB port, two serial ports and one AAUI port.