Question: 1. Why cannot the 68000 be used (in conjunction with the 68451 MMU) to design true virtual memory systems?
2. Why can the 68010, the 68020, etc., be used to design virtual memory systems?
3. How does the 68451 MMU make use of the 68000s function code outputs during an address translation?
4. The 68851 PMMU uses paging. If the smallest page it can handle is 256 bytes, the total address space devoted to page descriptors will be several times that of the 68000 entire address space. How does the PMMU avoid the need for a vast number of page descriptors?