A microminiature personal computer that is connected to external devices using standard interfaces for information input and output. The microminiature personal computer has an interconnected processor, a memory, a security module, a network module, and connectors. At least part of memory should be non-volatile to keep operating system, drivers to work with external devices, programs and data. The microminiature personal computer does all its processing and all its programs are running inside its memory while external computing device is used only for information input and output through a connector and a windowing system thus ensuring security of both systems and lack of unauthorized interaction between them.