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· Hardware
Hard Drives?
3 messages in this thread
Darryl, are you saying that the seagate isnt RLL compatable? Or can it be
used the way it is? Is the okidata a better although as you said cheaper
drive but better becasue its rll compat? Thanks in advance. J.S.
The Seagate 225 is a 20 MEG MFM (non-RLL) HD.
The Seagate 238 is the RLL version of the above.
The Okidata 526 is the equivalent of the Seagate 238 with 10% more
disk Capacity. (By the way, the Oki is faster than the Seagate. Both are
65 msec. drives, but the Oki seems to have better electroincs to move the
data faster into the Adaptec.)
General info: MFM refers to a method of putting data on a HD. RLL
is a different method that packs approx 1.5 times as much data on the same
HD (ie. a 20 meg drive becomes a 30 meg with RLL encoding). Most drives
will work as RLL even though they are not `certified' as RLL drives, but
using drives that way will cause a lot of data-loss later on because the
media (disk surface) simply is not good enough. Seagate, for example,
tests most all of their 20 meg drives for RLL, those that pass become
Seagate 238's those that don't wind up as Seagate 225's. RLL encoding
requires that the media be able to store 1.5 times the data normally
stored, and (just as importantly) that the electronics in the drive be able
to pass the data at 1.5 times the normal speed. All in all this is a very
demanding requirement.
The Seagate 225 is a 20 MEG MFM (non-RLL) HD.
The Seagate 238 is the RLL version of the above.
The Okidata 526 is the equivalent of the Seagate 238 with 10% more
disk Capacity. (By the way, the Oki is faster than the Seagate. Both are
65 msec. drives, but the Oki seems to have better electroincs to move the
data faster into the Adaptec.)
General info: MFM refers to a method of putting data on a HD. RLL
is a different method that packs approx 1.5 times as much data on the same
HD (ie. a 20 meg drive becomes a 30 meg with RLL encoding). Most drives
will work as RLL even though they are not `certified' as RLL drives, but
using drives that way will cause a lot of data-loss later on because the
media (disk surface) simply is not good enough. Seagate, for example,
tests most all of their 20 meg drives for RLL, those that pass become
Seagate 238's those that don't wind up as Seagate 225's. RLL encoding
requires that the media be able to store 1.5 times the data normally
stored, and (just as importantly) that the electronics in the drive be able
to pass the data at 1.5 times the normal speed. All in all this is a very
demanding requirement.