Minicomputers

Minicomputers are a class of time‑sharing computers designed for smaller workloads than mainframes, typically serving multiple users or devices at a lower cost. They emerged in the 1960s as midrange systems suitable for business data processing, scientific work, and laboratory control. The term distinguished these machines from larger, more expensive mainframes and from later microcomputer-based systems.

Early examples include DEC's PDP‑8, often cited as the first true minicomputer, and the PDP‑11, which became a standard in education, research, and industry. Other notable lines were Data General's Nova and Eclipse, and Hewlett‑Packard's HP 2100 and later HP 3000. These systems offered modular architectures, relatively affordable pricing, and capabilities for timesharing or interactive use, enabling multiple terminals to connect to a single computer.

Operating systems supported multi‑user operation, with UNIX first written for the PDP‑11 and later ported to many minicomputers. DEC's VAX line extended the concept to more powerful machines, while others offered real‑time or batch processing options. Minicomputers found use in process control, laboratory instrumentation, business data processing, and education, providing interactive access and sometimes dedicated control tasks that were impractical on larger machines.

The market declined in the 1980s and 1990s as microprocessors improved and personal computers gained networked access to servers. Many minicomputer lines were discontinued or transformed into midrange servers, and the term faded from common usage. Nevertheless, minicomputers helped establish timesharing, multi‑user operating environments, and the early UNIX ecosystem, influencing the design of later servers and workstations.