Introduction to basic digital electronic circuits: Combinational and sequential circuits, flip-flops, registers, memory, counters. Computer organization: Design of basic computers, hardwired and micro programmed control, programming a basic computer, instruction formats and addressing modes, stack organization. Computer architectures: RISC and CISC architectures, Parallel processing. Operating system: Introduction to operating system, functionalities of an operating system. Process management: creation, scheduling and termination of a process, light- weight process, Inter process communication, Deadlocks handling, process synchronisation. Memory management: static and dynamic memory, memory allocation methods. Input output management: Handling interrupts, Disk scheduling algorithms. File Management: File and Directory structures, allocation methods, free space management, UNIX file structure. System Security and protection methods