The Mac 128k was not from 1988. In that time frame, The Mac plus was the first really usable model with a 20MB HDD.
(apologies for hijacking the comment!)
Anyways, here's my response to walrus01:
The Mac 128k is a different model, check out the floppy slot!
3 years ago you committed the offence of punning on HN, https://news.ycombinator.com/item?id=5144413
e-mail the mods at hn@ycombinator.com
It wasn't internal but it was made for the Plus.
It was an odd beast that connected to the external floppy connector.
I didn't understand walrus01's comment to mean an external, rather than internal, hard drive.