A high level language computer architecture has been proposed as an alternative to the conventional computer architecture and software systems. MIDEX, which directly executes a high level simulation language, MIMIC, is proposed in this thesis. MIDEX is designed and implemented with multiple processor configuration consisting of a lexical processor, an execution processor, an I/O processor, and a control processor. Some design consideration is given, for efficient processing of HLL MIMIC including lexical processing. Another consideration for multi-user system is proposed.