Supported System Software: 7.1, 7.1.1(Pro), 7.5, 7.5.1, 7.5.3
SCSI: DB-25
Serial Ports: 2
Sound Output: stereo 8 bit.
ADB: 1
Ethernet: AAUI-15 built-in or upgrade to Newer Technology 7ET-N10/100
Machine Gestalt ID: 35

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.

Can be accelerated with Newer Technology’s "MacClip™", part # 7MC040-QC.  The world's smallest Macintosh accelerator.

Can interleave memory for approximately 10% faster RAM access.  For the fastest speed, sockets 1 & 2 or 3 & 4 should contain identical capacity SIMMs.

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.