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Thread: Imagedisk to 8" keeps using 500kbps for SD disks

  1. #21

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    Hi Al. I'm just trying to read a CPM directory that was written with imagedisk on the MDS225 which is running CPM 2.2.
    The MDS appears to be weird. I'm now finding that lots of old disks that I couldn't read on the MDS I thought were bad, will read on the xerox 820.
    So the MDS needs something specific in the gaps to work right and not all disks have that apparently.

  2. #22
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    No, I don't think so. Are you certain you don't have the Series II MDS with the double-density mod?

    In any case, IBM 3740 diskette format is pretty standard, so I don't think it's something in the gaps or DAMs or IDAMs.

    Try creating a single-density 8" ISIS-II boot disk from the bitsavers IMD

    Does it boot?

    P.S. You're not trying to use double-sided floppies for this are you?

  3. #23

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    This is an MDS II with integral drive (SS SD using 8271 chip) along with the SSDD board set cabled to external drives.

    I have a CPM that boots from the DD drive, that gives me access to the SD internal drive where I can read standard CPM disks.

    The problem is, if I try to copy a CPM disk via imagedisk, it wont read on the MDS SD drive like the original will.
    So imagedisk is changing something and not exactly copying.

    Only using single-sided floppies. Double-sided won't even produce an index pulse on a SS drive due to the hole location.

  4. #24
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    I'll have a look at a low-level at an IMD-formatted 8" floppy and see if there's anything different from standard IBM 3740 in AM's and gaps. Since you're using IMD, have you tried using 22DIsk's formatter?

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