cctech Digest, Vol 78, Issue 3

[Dave McGuire]

On Feb 5, 2010, at 7:01 PM, Chuck Guzis wrote:
>> Anywho the IDE interface chips from the PC market are all basically
>> 16bit wide bus, IDE drive 0,1 address decode and some extra logic to
>> do burst mode DMA, block DMA (Both required external DMA support) or
>> PIO. in the x86 space.  FYI PIO unlike floppies is buffered on the
>> disk so the IO can be does as fast or slow as the programmer  
>> wishes to
>> the limits of ATAPI spec (all do minimally 33mbytes/sec and later are
>> faster).
>
> Just about any IDE disk drive made in the last 20 years also has a 16-
> bit data path (very old XTIDE drives could do 8 bit, but they're hard
> to find.  I don't know about microdrives).  So that's a problem with
> or without an interface chip if what you want to do is interface to
> an 8-bit bus--and use all of the available space on the disk.

   Microdrives conform to the CF standard, which requires that the 8- 
bit mode be implemented.

            -Dave
>


-- 
Dave McGuire
Port Charlotte, FL