Supported System Software: 7.1, 7.1.1, 7.5, 7.5.1, 7.5.3
SCSI: DB-25
Serial Ports: 2
Sound Output: stereo 8 bit.
ADB: 1
Ethernet: use Newer Technology 7ET-L10 or 7ET-C10
Machine Gestalt ID: 92

Minutiae:

Apple sometimes advertises this as a 66 MHz machine, since the clock speed is doubled inside the processor chip.  However, all I/O to the processor is done at 33 MHz. 

Original Enabler: 065

Serial Port with the phone icon supports synchronous modems, with handshaking on both output and input supported.

Has 1MB ROM and a 1.44MB SuperDrive.