Re: Extracting files off “unknown” 8 inch disks. Any thoughts…

Fred Cisin cisin at
Fri May 5 15:14:27 CDT 2017

On Fri, 5 May 2017, Chuck Guzis via cctalk wrote:
> I didn't mean what I think you thought I meant.
I apologize

> The immediate problem
> is getting data--any data at all.   If you can retrieve every sector on
> the disk, then it's just a matter of software to unravel the filesystem.
> DEC filesystems in general are pretty well documented, even if you have
> to wade through the strangeness of things such as RAD50 file names.

Sometimes easy, sometimes not

> Yes, flux-transition (e.g. catweasel) tools do exist for RX02
> double-density reading and writing.  I've used them in the past. At
> least one runs under Linux and allows one to copy dd-style sector by sector.

good to know!
I don't anticipate doing any, but I'm glad to see that somebody has put 
such together.

> But first you need the bits.  Without those, the filesystem is just a
> useless abstraction.

Quite true.
But, it turns out that there are multiple people handy who happen to have 
the machine.  And they could TRIVIALLY accomplish what we would have to 
put a little bit of work into.  If there weren't, then the next step 
would, indeed be to look at raw images of tracks.

> Data first--interpretation later.

Although, when I have an "unknown" disk, before I launch a sector editor, 
I type "DIR", just in case it ISN'T anything challenging.  I didn't try 
flux-transition until I failed with my sector editor.

Grumpy Ol' Fred     		cisin at

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