IBM ThinkPad 380ED — The 380ED model was virtually identical to the 380E, but with the 166 MHz processor standard, a 0.3 pounds increase in weight, an optional 2.5-hour battery along with the model standard two-hour version, and a gradual increase in hard drive size from 2.1 to 3.2 GB, and then to 5.1 GB (which became optional for the older models).