[Coco] Coco Memory

[Paul Fitch]

I've got a question that s been bothering me off and on for decades.

The Coco under basic can easilly see 32k, and 64/128 K with ML routines.
When the Coco3 came out, MS-dos intel machines using 8086/80186 processors
could access and use 640k.  What was intel doing differently from Tandy to
allow that odd non-base 2 memory amount? Ie, 1k, 2k, 4k, 16k, 32k, 64k,
128k, 512k, 1-meg, 2-meg.  640k falls in the middle there.  What were they
doing that was so strange that the coco couldn't do it to?