Choose the appropriate tense between Past Simple / Present Perfect and use the right form 1. Since computers were first introduced to the public in the early 1980s, technology (change) ................................. a great deal. The first computers (be) ................................. simple machines designed for basic tasks. They (have, not) ................................. much memory and they (be, not) ................................. very powerful. Early computers were often quite expensive and customers often (pay) ................................. thousands of dollars for machines which actually (do) ................................. very little. Most computers (be) ................................. separate, individual machines used mostly as expensive typewriters or for playing games.