On 23/07/2014 4:34 PM, smf wrote: >> As long as the controller board on the actual drive is from the same >> model you can swap it. > > Sure, the original point was with separate boards that you were forced > to replace controller boards with the same one or you wouldn't be able > to access the existing contents & to use the drive you'd have to low > level format it and start again. My point about IDE is you have the > same problem, except you can't always just low level format it and > start again because the controller firmware is on the drive. > >> The only problems where with the early PC's where you could only >> select from a select amount of definitions (and couldn't enter your >> own to suit the drive, or autodetect), but that's a seperate issue >> entirely. If a drive worked with one of those systems but the logic >> board on the drive died, you could certainly replace the logic board >> from another drive and you could retrieve the data. > > That isn't MikeS's experience and I'm pretty sure I've seen it happen > to. The last MFM controller I looked at documentation for stored the > drive geometry on track 0 during low level format, which I'm pretty > sure is controller specific. Even if the data tracks are stored in a > compatible way (which isn't a high chance) then I believe track 0 is > going to cause you issues. > > When I said early PC's, I meant early PC's with fixed IDE definitions in the BIOS. XT class machines didn't store drive definitions in BIOS, that was the job of the controller. I have retrieved data from MFM/RLL drives using random controllers simply because the controller had a drive definition that was close enough, or supported the most common drives but it was hit and miss. Message was sent through the cbm-hackers mailing listReceived on 2014-07-23 12:00:02
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