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Thu, 16 Apr 1998 12:44:25 -0800 |
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On 15 Apr 98 at 21:49, Herbert Graf wrote:
> > I don't see where 6EA comes into it. Maybe you're talking about
> > something else.
>
> I believe what the person was talking about is correct. You see, some
> cards do not properly decode the full address, they only decode certain
> address ranges present in the original XT. Because of this, some cards
> might respond to more than one address, it is a common problem on older
> cards designed under budget. TTYL
Oh, okay, I see. Javier's suggestion was based on the assumption
that the conflict at I/O address 2E8 was an artifact of the original
PC design decision to use only the lowest 10 bits of the address.
But that's *not* what's happening in this case. COM4, by default,
wants addresses 2E8-2EF and 8514/A calls for addresses 2E0-2E8,
and neither provides high bits that would avoid the conflict at 2E8.
David G
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