Replying to a message of Craig Hart to Darryl Gregorash:
 CH> Port 80h is the POST diagnostic status port - the
OK, thanks.. as I said, it wasn't in the lists I have here, the newest of 
which is several years old.
 CH> As for port 81h bieng next to port 80h, well, so what. Just
 CH> because they're numericly next to each other does NOT mean
 CH> they're going to somehow conflict. To suggest otherwise
 CH> would be to suggest that all PC hardware must be designed
 CH> in such as way that no I/O port is numericly next to
 CH> another one -- clearly this is NOT the case.
No, to suggest otherwise would not be to suggest that at all.. you are 
implying that I am suggesting that half the i/o ports should never be used at 
all. My comment to which you replied was very narrowly made, and does not 
warrant such a broad generalizing presumption of intent.
What I did say was that, since 81h is used by a DMA controller, I would not 
want to use 80h if it were free for use.. the reason for _that_ should have 
been obvious, and I thought it was: some possible future DMA controller might 
assume it is free, and the system designers could then begin using it, 
destroying the usefulness of any code such as we are discussing, which relied 
on the port being free. 
I guess you must have missed the part (which you did not quote) where I said 
making any assumptions about a port being forever free for use for the 
purposes being discussed here is dangerous, and focussed instead on a minor 
explanatory comment made in response to a subsequent question I was asked.. 
that is the only reason I can think of for taking the very narrowly drawn 
comment I did make, and then over-generalizing it to the point of silliness.
--- FleetStreet 1.20 NR
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