IBM PORTABLE COMPUTER (1975)
IBM introduced the 5100 Portable Computer in September 1975. The machine weighed around 50 pounds and was a little larger than a typewriter. Though it may appear clunky compared with today’s computers, the 5100 was significantly smaller than the era’s other computers with similar capabilities; it could use both the APL and BASIC programming languages and could be equipped with up to 64 kilobytes of memory. Fully loaded, the 5100 cost around $20,000.
Technology Review: 100 Years of IBM in Pictures.