Problems reading old floppies (PC and Amiga)

[wardle]

I think my set-up is working (Mac with GreaseWeazle 4.1 and a new 3.5" Samsung floppy disk connected using a straight ribbon - not a twisted one if that makes any difference). I did manage to read one (commercially written) IBM PC HD floppy (1440) but typically that was the only one I really didn't want - into an IMG file and even on opening that, the files appear corrupted and will not open. The rest of my floppy disk collections show repeated errors:

e.g.

mark@mbp21 Desktop % gw read psiwarriordemo.adf --revs 6 --drive=b
Reading c=0-79:h=0-1 revs=6
Format amiga.amigados
T0.0: AmigaDOS (8/11 sectors) from Raw Flux (272999 flux in 1363.62ms)
T0.0: AmigaDOS (8/11 sectors) from Raw Flux (267999 flux in 1350.55ms) (Retry #1.1)
T0.0: AmigaDOS (8/11 sectors) from Raw Flux (267576 flux in 1352.84ms) (Retry #1.2)
T0.0: AmigaDOS (8/11 sectors) from Raw Flux (268111 flux in 1356.02ms) (Retry #1.3)
T0.0: Giving up: 3 sectors missing
T0.1: AmigaDOS (11/11 sectors) from Raw Flux (264772 flux in 1353.64ms)
T1.0: AmigaDOS (0/11 sectors) from Raw Flux (271788 flux in 1371.46ms)

Switching to raw flux obviously works:

mark@mbp21 Desktop % gw read psiwarrior.scp --revs 6 --drive=b
Reading c=0-81:h=0-1 revs=6
T0.0: Raw Flux (265650 flux in 1278.41ms)
T0.1: Raw Flux (266602 flux in 1337.51ms)
T1.0: Raw Flux (274287 flux in 1313.44ms)
T1.1: Raw Flux (266081 flux in 1334.93ms)

And if I load the resulting file into HxCFloppyEmulator I get this - which to my uninitiated eye looks bad!

Is there a good way of rescuing at least some of the data from some of these disks, or an aspect of my set-up I can check and improve to make recovery more likely? The floppy disks sound awful in the drive - should I be cleaning each disk before to use, or considering a different floppy drive that might perform better with less-than-optimal old disks?

Any advice appreciated!

mark@mbp21 Desktop % gw info
Host Tools: 1.22
Device:
  Port:     /dev/cu.usbmodem2101
  Model:    Greaseweazle V4.1
  MCU:      AT32F403A, 216MHz, 224kB SRAM
  Firmware: 1.6
  Serial:   GWB049C8185976C01007859705
  USB:      Full Speed (12 Mbit/s), 128kB Buffer

Many thanks

Mark

[keirf]

You probably need to clean the disk. Not only do dirty disks read badly, they can also contaminate your drive, and in worst case damage the drive heads. Pull the shutter back and take al ook for signs of mould, dirt, or oxide shedding.

[wardle]

Thank you that is really helpful. Will try this. And thank you very much for such an amazing board and software - very impressive!