alex@grian.cps.altadena.ca.us (Alex Pournelle) (12/06/89)
kaleb@mars.jpl.nasa.gov (Kaleb Keithley) writes: >In article <11470001@acf5.NYU.EDU> mitsolid@acf5.NYU.EDU (Thanasis Mitsolides) writes: >>Hi, >> A friend of mine has a 72mb MFM drive (ATASI 3085) and >>he would like to try and format it using an RLL controler. >> >I have successfully RLLed both Seagate and Micropolis MFM drives. Make sure >you run the RLL controllers surface scan, and add found defects to the bad >track list. The only difference between an Rll and an MFM drive is that the RLL drive has been qualified for RLL use. In some cases, that's the ONLY difference! The MiniScribe 3650 and 3675 are the same drive--the difference is that the second got window margin testing and the first did. You may find creeping failure of your drive, though. A well-known problem with using non-RLL-qualified drives (ST-225, cf.) is that they may format Ok, then slowly start going bad--getting many bad sectors over a period of a few days, a few weeks, a month, just when you need the data. You can somewhat "test to destruction" this problem by using SpinRite II (yes, there's an update--and it works on big partitions, fokes) on your drive at "deepest level" pattern testing. However, it can take a day... My advice, speaking as someone who recovers dead hard drives for a living: Don't use RLL if you depend for a living on that drive. If you must, then use only well-known RLL-certified drives, and get someone who knows what they're doing to set it up. Initialize and format the drive at low (non-turbo) system speed. Testing can be done at high speed; certainly interleave testing must be. Get a well-known RLL controller too. If your controller goes the way of the great Auk, you should still be able to get at your data! I have several customers with no-name controllers where I can't get the data off, period, because we can't get a compatible controller! And it saved them a whole $5.00... If you use an AT, don't save $10 by using an 8-bit controller. You're asking for trouble if you don't use a real 16-bit controller. We're a Western Digital shop, but that doesn't mean they're the only ones. If you really want to double the capacity of your hard-drive, use a Perstor controller board. It will give you 90% higher capacity with 2 orders of magnitude better error correction. It will only do 3:1 or (maybe) 2:1 interleave, but the throughput is still impressive. It is NOT dead-simple to install and use--it is a little more difficult, and I wouldn't recommend it to a neophyte for installation unless he had a really good dealer. But once installed, the Perstor controllers really work--we have quite a number of very happy customers. Hope this clears the air some. Alex