Service manual

System Overview 1-25
The rules for addressing memory are as follows:
1. Address space is determined by the memory pair in slot MEM0.
2. Memory pairs need not be the same size.
3. The memory pair in slot MEM0 must be the largest of all memory pairs. Other
memory pairs may be as large but none may be larger.
4. The starting address of each memory pair is N times the size of the memory pair
in slot MEM0. N=0,1,2,3.
5. Memory addresses are contiguous within each module pair.
6. If memory pairs are of different sizes, memory “holes” can occur in the physical
address space. See Figure 1-16.
7. Software creates contiguous virtual memory even though physical memory may
not be contiguous.