25 May
2016
25 May
'16
12:17 a.m.
Am 25.05.2016 um 06:45 schrieb drlegendre .:
It may, in fact, be possible - with custom ROMs - to
use the 1541 for other
formats. But it's telling that no one, so far as I know, has ever managed
to create software to 'tween the various 5-1/4" floppy formats, using the
1541 transport & hardware.
The 1570/71/81 drives have a dedicated WD controller
chip for the
compatible MFM formats.
I doubt that even with a custom ROM it would be possible to cleanly
bit-bang MFM instead of GCR to the
data/clock port to the drive. With the GCR encoding home-grown by
Commodore there were no tight
restrictions to the data rates that are enforced by IBM compatible
formats; they could invent any rate
their hard- and software could manage.
Holger
On Tue, May 24, 2016 at 8:43 PM, Cameron Kaiser
<spectre at floodgap.com>
wrote:
>> A fellow has made up a nice adapter to read and write Commodore disks on
>> a PC via USB using a 1541 drive.
>>
>> The thing that jumped out at me is that this is a 5 1/4" drive that
>> reads and writes via USB. Anyone want to comment on whether the
>> floppies it accesses would be useful other than on the C64?
>> Could one do say 360K floppies via this hardware for other than the
>> Commodore? At least part of the work is done to do more than just
>> archival like Catweasel, et. al. do, in that it can also write.
> The X*1541 cables (this would be an xum1541) still talk to the drives at a
> relatively high level, since the 1541/71/81 family are all intelligent
> peripherals. So:
>
> For the 1541, which is strictly Commodore GCR, no.
>
> For the 1571, which can do a variety of MFM formats, maybe, but I'm not
> aware that OpenCBM supports that. On the other hand, since it's MFM, you
> could easily just use something else.
>
> --
> ------------------------------------ personal:
> http://www.cameronkaiser.com/ --
> Cameron Kaiser * Floodgap Systems * www.floodgap.com *
> ckaiser at floodgap.com
> -- Diamonds are forever.
> ------------------------------------------------------
>