Weighing in at less than 5 lb., the Radio Shack TRS-80 Model 100 was one of the first portable computers known as laptops. Released in 1983, the Model 100 was powered by a 2.4-MHz processor with 32 KB of memory. The base model retailed for $799 and included applications like a word processor and an internal 300-baud modem. Four alkaline AA batteries could power the Model 100 for up to 20 hours. You'd be lucky to get four hours on a standard laptop nowadays with that.