gatesl@romana.cs.orst.edu (Lee Ryan Gates) (05/18/89)
Well, in followup to the discussions about ARLL and RLLing ST-251's, i am
posting what I decided on. I figure the Perstor would probably not be worth
the extra 120$ (300 vs. 180) for the little bit of extra space, and having to
compromise the 1:1 interleave. Today I got the DTC 1:1 RLL controller. All
went well, transfer rate climbed to 659kb/s from the MFM 2:1's 239kb/s, it
formatted the 42.7mb to 65mb, and found the same if less errors in formatting.
I am quite pleased with the outcome. I got some responses from others on the
net before, all positive. The only requirement one person noted (from a
previous disscussion) is that the window margin on the spec sheet from Seagate
had to be < 60ns, mine was in the 30-40 range, so no problems. The only
negative information I found was in Computer Shopper in which a guy wrote in
that he had RLL'ed a Miniscribe 3650 (standard MFM drive), then 4 months later
had a software crash in which the drive lost all data. I have gotten respose
from others who have done the same thing with 251's with success, so I am not
very worried (I will keep frequent backups however).
Just thought I would inform you to my decision, and outcome. Please let me
know if you have any comments or questions.
lee
**
'must be Oregon, look there's another person with rust on 'em.'
gates@romana.cs.orst.edu 'anybody got a job for an aspiring cs undergrad?' :-)karl@ddsw1.MCS.COM ([Karl Denninger]) (05/19/89)
>Item 3376 (0 responses) by gatesl at romana on Thu 18 May 89 12:36 >[Lee Ryan Gates] Subject: 2ST-251-1 + 1:1RLL = Success! >had to be < 60ns, mine was in the 30-40 range, so no problems. The only >negative information I found was in Computer Shopper in which a guy wrote in >that he had RLL'ed a Miniscribe 3650 (standard MFM drive), then 4 months later >had a software crash in which the drive lost all data. I have gotten respose Yeah, but he probably would have taken that hit in MFM mode too.... The Miniscribe 3650s are known to be pieces of junk, or at least were a year or so back. No idea how they are now; we aren't about to try again. One thing to watch out for -- Northgate used to use these monsters in their machines, with RLL controllers. No idea what they use now. I wonder what their failure rate on these drives has been like. An ST251 is just a ST277R without the higher level certification; if you want the ability to return it to your dealer if there is a problem 6 months down the road get the 277R; they're not that much more expensive ($75 or so), and probably worth the piece of mind. If you already have the ST251, you've nothing to lose. Go for it. Nearly 95% of those we have tried have worked fine, and our experience goes back over a year. No failures yet (save one head crash which decidedly was not due to anything related to the encoding method). -- Karl Denninger (karl@ddsw1.MCS.COM, <well-connected>!ddsw1!karl) Public Access Data Line: [+1 312 566-8911], Voice: [+1 312 566-8910] Macro Computer Solutions, Inc. "Quality Solutions at a Fair Price"