The Macintosh Portable sports the traditional clamshell case design we all know and love today, but the unit overall was far bulkier and heavier than later Mac laptops.
The Portable packed a 10″ monochrome screen, weighed 16 pounds, and measured 15.25″ by 14.8″ by 4″ when closed. Compare that to today’s largest mobile Mac, the 17″ MacBook Pro: the modern MacBook has a far larger (and vastly more colorful) screen, yet weighs only 6.6 pounds and measures 15.47″ by 10.51″ by .98″. (Yep, the Portable is four times thicker than the MacBook Pro.)
The Mac Portable required Mac OS System 6.0.5 to run, but supported up to System 7.5.5. Interestingly, it was the first Macintosh to ship with Mac OS pre-installed on its hard drive (if you bought that option).