> -----Original Message----- > From: Christian Corti via cctalk <cctalk@classiccmp.org> > Sent: 20 January 2023 09:34 > To: ClassicCmp <cctalk@classiccmp.org> > Cc: Christian Corti <c...@informatik.uni-stuttgart.de> > Subject: [cctalk] Re: Computer Museum uses GreaseWeazle to help exonerate > Maryland Man > > On Thu, 19 Jan 2023, r...@syssrc.com wrote: > [... blob of text ...] > > It had been written on a DEC PDP-11 minicomputer using the RSX-11 > > Operating System. Although the museum has a PDP-11 in its collection, > > it had not yet been restored and could not be started. Brendan > > Becker, > [...] > > Brendan set up a ?Greaseweazle,? a device that reads the magnetic flux > > transitions on the floppy disk without regard to operating systems, > > disk > [...] > > Isn't that a bit overcomplicated? I mean, they *are* standard IBM format > floppys that can be read with a normal PC floppy controller. > I really wonder why the museum did not know this. Maybe even PUTR could > have been used to copy off the files from the disks.
They can, but once you hit a read error a PC goes into re-try mode and you run the risk of dirtying the heads and damaging the disk. With one of these tools you read the flux transitions of the disk, so a whole track and then sort the data out. This reduces the risk of damaging the disk and the drive. > > > Christian Dave
