Implemented and modified an operating system by using C on UNIX. Contents: Synchronization, multiprogramming, CPU scheduling, and I/O instructions. Designed a compiler by using C and Pascal on MS-DOS. Contents: Lexical analyzing, symbol table, parsing, and machine code instructions. Designed 16-bit CPU. Contents: Data path, control signals, register transfer level descriptions, logic designs, and diagrams. Microprogrammed the emulation of a 32-bit microcomputer on a single chip.