Where is the computer located on a 1990 Chevy Camaro?

There is no computer in the sense of a central processing unit like a desktop or laptop in a 1990 Chevy Camaro. A 1990 Camaro uses a simpler Engine Control Unit (ECU), sometimes called a Powertrain Control Module (PCM), which is a type of embedded system. It's a specialized computer, but not a general-purpose one. This ECU is located under the hood, usually near the firewall. Its exact location will vary slightly depending on the engine and trim level.