Power, USB 1.1, serial port 1 (DB-9, RS-232), parallel port, twisted-pair Ethernet, SCSI, and the audio card. The PCI slots from top to bottom: Slots 5 and 4 are 66 MHz/64-bit. Slots 3 and 2 are 66 MHz/64-bit. Slots 1 and 0 are 33 MHz/64-bit.