RLL vs. MFM

[Geoff Reed]

At 04:53 PM 3/8/2005, you wrote:
>Some people even did it on purpose, back in the day... I remember
>people putting a
>Seagate ST-238R on an MFM controller and getting the expected 21.4MB.  The
>reason for doing it on purpose was to de-rate the drive in the
>expectation of fewer
>bad blocks, and longer-term reliability.  Dunno if that really works,
>but at the time,
>there was this expectation that it should work, certainly better than
>trying to format
>an ST-225 as if it were an ST-238R. (I think it was assumed that Seagate 
>already
>had qualified their own platters and labelled the drives accordingly)

i used to get burnt up 225's for free from a local shop and replace the 
amplifier chip on them (think it was an amp, i don't remember for certain 
anymore)  the chip just cuoldn't handle the higher frequency and datarate 
that the drive was subjected to if run RLL, heck they chips fried 
themselves eventually if you ran them MFM, the bloody think needed 
heatsinked, but it was on the side of hte PCB against the bottom of the 
drive....