The Portable PC was IBM's first carry-around PC. It still needed to be plugged in to work and weighed 30lbs, so it was quite a chore to carry around. Introduced in 1984, it offered an XT in a small box. It used the same motherboard as the XT but included a 9" Amber screen built into the case. The keyboard attached to the front of the case making it very simple to carry around, if you could handle the weight of it.
Although the screen is truly ugly (I have seen it), it is a very nice machine to get your hands on if you can find one. I like older computers, and especially different ones like this one. I wouldn't mind finding any portable machine to fix up, but one like this is portable, but also completely compatible with the bigger machines with very few exceptions. Since 6 expansions slots are left for items like a modem and Hard Card, you could turn one of these into a vintage internet surfer like I have done with my XT. If you don't want to spend a thousand dollars for a laptop so you can check your e-mail while you are away, try to find one of these and as long as you don't want to carry it around with you it will work just as well as a more expensive one would.
This is the machine I most want to find of all the old computers out there. I hope someday to find one of them sitting somewhere and pick it up and cheap and hopefully get it up and running. If you have one yourself you may or may not agree that they were a good idea at the time, unless you had to carry one around for any length of time.