SCSI: DB-25
Serial Ports: 2
Sound Output: stereo 16 bit.
ADB: 1
Ethernet: none
Machine Gestalt ID: 515
PRAM Battery: 4.5V alkaline (Rayovac 840)

Minutiae:

Can be accelerated with Newer Technology's 512KB Cache DIMM, part # 7CC512C.

The 4400 can take only 3.3 volt EDO DIMMs.  It does not support interleaved memory.  The three DIMM sockets are NOT identical.  The first socket can only accept up to 32 MB DIMMs.  The other two sockets can accept up to 64 MB DIMMs.  The maximum memory is therefore 160 MB.

Has 4MB ROM and a 1.44MB SuperDrive.