5 Nov
2010
5 Nov
'10
3:05 p.m.
> 20 years would have to include
"RLL" and ESDI (RLL has same cabling as
> ST412, but different encoding and data-rates? , ESDI cabling looks the
On Thu, 4 Nov 2010, Tony Duell wrote:
Eh? RLL is a date encoding scheme, ST412 is a
de-facto stadnard for the
signals on the drive interface connectors. They are not the same thing at
all.
Thanks. I got sloppy. This is one situation where I should have said "MFM", or clarified the comparison as
"ST412 MFM", since I was trying to
say that the RLL drives were cabled the same, but the data transfer rates
and encoding may be different.
IIRC, the pulse rate at the interface connector is much the same, it's
just a more efficient encoding scheme, using more of the possible patterns.
ESDI
cabling looks the same but has signal differences)
It's very different... For
one thing the data separator is in the drive
(meaning the encoding method doesn't matter to the end user). FOr
another, head position, etc, is done by sending a command bit-serially to
the drive.