How to read Osborne 1 Floppies?

Fred Cisin cisin at xenosoft.com
Tue May 25 22:04:17 CDT 2021


That should presumably do just fine.  It is PROBABLY the MFM Double 
Density format for the Osborne 1.  But, more likely than not, that is 
probably what they have.  The early FM Single Density wasn't around for 
long.

'course next step is for him to find a working machine with a 5.25" drive!
(preferably "360K")


On Wed, 26 May 2021, Tom Hunter wrote:

> Sorry - I misread the post thinking Zane wanted to get raw disk images.
> For the actual CP/M contents you can use cpmtools:
> http://www.moria.de/~michael/cpmtools/
> Cpmtools has disk definitions for the Osborne 1 and Osborne Nuevo/Vixen/4
> so it is rather painless.
>
> Best regards
> Tom Hunter
>
> On Wed, May 26, 2021 at 12:38 AM Fred Cisin via cctalk <
> cctalk at classiccmp.org> wrote:
>
>> Imagedisk is great for making images.
>>
>> BUT, the original request is not for images, it is for the previous
>> owned wanting access to be able to use the content of the FILES that are
>> in those images.
>>
>>
>> On Tue, 25 May 2021, Tom Hunter wrote:
>>
>>> Dunfield's ImageDisk reads and writes them just fine on most older PCs
>> with
>>> a decent floppy controller.
>>> As Chuck G writes "TestFDC" will tell you if the floppy controller is
>>> usable for imaging.
>>>
>>> Best regards
>>> Tom Hunter
>>>
>>> On Tue, May 25, 2021 at 2:26 AM Fred Cisin via cctalk <
>> cctalk at classiccmp.org>
>>> wrote:
>>>
>>>> There were two Osborne floppy formats.  Both CP/M.
>>>>
>>>> IIRC, the original format was "Single Density" (FM), 10 sectors per
>> track,
>>>> with 256 bytes per sector (similar to the TRS80-Model-1.  That will
>>>> require FM/SD capability.  Most NEC FDCs did not support that.  Dave
>>>> Dunfield has a test program that will tell you whether your FDC can
>> handle
>>>> it.
>>>>
>>>> Then, they switched to "Double Density" (MFM) IIRC: 5 sectors per track,
>>>> with 1024 bytes per sector.  Any PC FDC with access to INT13h and INT1Eh
>>>> will work with appropriate software.  (NOT external USB drives)
>>>>
>>>>
>>>> WITH appropriate software, a flux transition device, such as your
>>>> Catweasel, could do it.
>>>>
>>>>
>>>>
>>>> On Mon, 24 May 2021, Zane Healy via cctalk wrote:
>>>>
>>>>> A photographer I know contacted me last night asking about reading
>>>> Osborne 1 floppies.  What does it take to read these?
>>>>>
>>>>> The only Catweasel board I have is the old Zorro 2 board for the Amiga.
>>>> I do have 5.25” floppy drives.  Neither of us have an Osborne anymore (I
>>>> think mine went to Jim Willing).
>>>>>
>>>>> Zane


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