24 Nov
2005
24 Nov
'05
10:19 p.m.
On 11/24/2005 at 8:45 PM ard at p850ug1.demon.co.uk wrote:
(taking a break between putting the turkey in the oven and making the
cranberry sauce)
Are you sure the SED9421 is not a complete data
seperator? The PCB I am
looking at (from an Epson PF10 drive unit) doesn't seem to have much else
around the 765 disk controller chip.
I was trying to interpret the Japanese comments--it's entirely possible
that the writer was simply drawing a parallel to the 9420, not saying that
the 9421 used the 9420.
Has anyone noticed a significant performance difference between the PLL
type data separators (e.g. the WD1691/2143 combo) and the plain-Jane WD9216
digital ones? I suspect that the PLL type is more tolerant of drive speed
variations, but that hardly matters all that much with modern drives. I
don't recall finding a disk that failed to read on a generic 9216-equipped
FDC but read fine on the old IBM PC floppy board.
Cheers,
Chuck