The following is inferred largely from the hardware documentation.

@i(Why You Don't Need Local Memory on the Processor Board to Boot Up a K/Mac:)

Initial virtual --> physical memory map built into the processor board.
Mac sets up initial part of memory;
in so doing, the Program Counter is initialized on processor memory board:

@example
Processor Memory Board ---> Initial Map ---> Physical Memory Board
@end(example)

PC (a valid virtual address) is then translatable into a physical address.

Low memory is always in the cache (IR cache?).
Cache misses may be only way to fill it -- can cache misses even occur?

Issue:	Can the communication area exist in low memory?  Is cache conflict
a problem?
Is there instruction caching, but no data caching?? Ask Rick.