Re: bad144 - how useful still? Because it's annoyingly ubiquitous.

On 2026-05-31 23:36, Jason Thorpe wrote:
> 
> 
>> On May 31, 2026, at 12:25 PM, Thor Lancelot Simon <[email protected]> wrote:
>>
>> Yeah, I was thinking about that.  But having to create new filesystemsis a
>> little different from having to do a full format in ignorance of whichblocks
>> were already marked as bad.
> 
> It also probably wasn’t very common to do this kind of cross-platform device-swapping back then.  And I suspect that people who did it were perfectly OK with “welp, gotta low-level format!”.
> 
> (Actual grey-beards, please chime in!)

I'm not sure I can remember much about moving and disks around. But just 
reflecting on it, I don't see why you would need a low level format in 
general. I think the low level format as such was the same no matter 
which system you connected the disk to.

The file system obviously was different. And also, DEC had this bad 
block information on the last track. But you didn't have to format the 
drive to create that. Manufacturers sometimes put a list on the drive, 
listing the bad blocks. And you could scan all of the disk to detect bad 
blocks as well. DEC certainly had tools to do just that, so you could 
get an updated bad block list on the last track.

   Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: [email protected]             ||  Reading murder books
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