PRAM Battery: 3.6V lithium (Maxell ER3S, Radio Shack 23-026)
Minutiae:
Requires symmetric memory. This is only an issue when dealing with SIMMs which use 16Mb chips. SIMMs built with symmetric chips are indicated by an "L" suffix on the part number.
Serial Port with the phone icon supports synchronous modems, with handshaking on both output and input supported.