5 Feb
2010
5 Feb
'10
4:01 p.m.
On 5 Feb 2010 at 18:17, allison 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.
--Chuck