SCSI: DB-25
Serial Ports: 2
Sound Output: stereo 8 bit.
ADB: 1
Ethernet: none
Machine Gestalt ID: 99
PRAM Battery: 4.5V alkaline (Rayovac 840)

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. 

Upgraded with one SIMM at a time. The SIMM socket closest to the CPU (the inner socket) can only accept a single sided SIMM. These SIMMs may be 1MB, 4MB, or 16MB in density. The outside SIMM socket can accept any standard 72-pin SIMM such as 1MB, 2MB, 4MB, 8MB, 16MB or 32MB.

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.