1. The X25-Demodulator machine does not provide a mechanism for interrupts; any process in the X25 OS is non-preemptive. In addition, the OS does not provide a means for selecting the next job to run. Provide the design and justification for your mechanism that supports process dispatching.

2. A spawned process (child) may proceed independent of the parent, as one method of OS process hierarchy management; another design is to have spawned processes directly linked to its parent, thus a child may only exist if the parent exists. Discuss the design advantage and disadvantage of each approach throughout the process lifecycle.

3. Given a virtual machine design where guest operating systems run as independent virtual machines supported by a host operating system. Detail the considerations that are involved in selecting a target operating system to serve as a potential host for the design and implementation of a virtual machine monitor that would support a specific guest operating system.

4. The X25-Demoulator machine has been upgraded to modern computer architectural standards. Additionally, the X25 OS supports pre-emptive multitasking and a one-to-one relationship between user-level threads and kernel-level threads which allows one or more threads from a process to issue blocking system calls while other threads (within that process) continue to run. Explain with design detail how the X25 kernel may provide for a user-level thread implementation?

5. Is operating system reliability and protection enhanced with the microkernel approach to system design?