RL02-USB Controller Status/Problem

Pete Turnbull pete at dunnington.plus.com
Tue Apr 7 08:14:18 CDT 2015

On 07/04/2015 11:21, Johnny Billquist wrote:
> Sp, to get to the meat of it. No, bad blocks are not replaced, or mapped
> away, or faked. The drive and controller can detect bad blocks, and when
> you try to read one, you'll get an error back. Drivers try a few times,
> and then give up, giving an error back to the user program.
> You should not try anything different.


> Copying RL disks with a block by block copy is not something you'd do.
> You'd mount the disk and copy the contents.

Actually COPY/DEV under RT-11 is commonly used, especially for non-RT-11 
packs.  I can't remember what RSX does, but RT-11 /does/ deal with the 
bad block table, by not copying the last track, and copying remapped 
blocks.  But in general, under other OSs, yes, not a good idea.  It 
would be like using dd in Unix to copy an entire device, including the 
disk label, rather than the partitions.


Pete Turnbull

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