I have been using a portable computer for nearly 4 decades.
A fellow Chem E, one who was writing books (and created a computing publishing house) about computer programs felt he could create a better computer than any had offered to date. So, in 1981, Adam Osborne did just that. He offered a portable computer (weighing in at a svelte 22 pounds), with a 7 inch screen, and two 180 KB 5 ¼ inch flopping drives. I had three of them- and replaced them when he offered up 360 KB drives- double the storage! (The last floppy I used stored about 3 MB!)