Q1. For each type of the following operating systems, find at least one example of a real OS (name, version, etc.): a. Mainframe/Server OS b. Personal Computer Operating Systems c. Handheld/Mobile Computer Operating Systems d. Embedded Operating Systems e. Real-Time Operating Systems Q2. What is the difference between kernel mode and user mode? Why is this difference important to an operating system? Q3. requests. DMA is designed to avoid increasing the CPU workload in handling I/O a. Describe in no more than ten sentences how DMA works? b. On some early computer systems, the CPU handles each byte of data read or written with I/O devices because there was no DMA. What implications does this architecture have for multiprogramming? Q4. List at least three designing differences between personal computer operating systems and mainframe operating systems.