At 7:21 Uhr +0100 13.11.1997, Ken Nakata wrote:
>On Wed, 12 Nov 1997 23:51:27 -0500,
>Allen Briggs <briggs@puma.macbsd.com> wrote:
>>
>> Nope.  I highly doubt that Apple used a standard IDE chip/cell.
>
>Would you care to explain what you mean by "standard IDE chip/cell"?
>I thought IDE controller chip is located on the drive, and the signals
>are identical to those of ISA bus except for the device select signals
>(which are generated by decoding higher bits of the address bus).
>
>Is it only I who think it'd be cheaper to use the "industry standard"
>parts? ;-)

Well, the main reason why IDE exists at all is that you get along with a
parallel interface (something like two 74HC245s) and a few control lines on
the host side. No need for "industry standard" parts here.

Where the ports are mapped and how they interrupt is more a question of
system integration than of the actual IDE "hardware".

	hauke



--
"It's never straight up and down"     (DEVO)