Here are a couple of technical tidbits for you...
The Macintosh 128 & 512 had 20 bytes of PRAM.
The Plus, Mac II, SE, SE/30, IIx, and IIcx bumped that up to 256 bytes of PRAM.
The Portable shipped after all of those, but only had 128 bytes of PRAM. Worse still, Apple did not allocate the bytes...