I'll upvite you if you can answer correctly

Figure 1 shows how to use the 74ALS138 3 to 8 lines decoder to decode an 8 -bit I/O address into 2 ports. a) Is memory-mapped or isolated I/O used in Figure 1? Why? (4 marks) b) Is fixed port or variable port address is used in Figure1? (4 marks) c) Show how to obtain the address of each port. (7 marks) Figure 3