Ultimate FDC? (Was: IBM 6360 - Filesystem(ish) info?

Fred Cisin cisin at xenosoft.com
Wed Feb 20 19:08:15 CST 2019

> > Ability to read MFM data with FM headers (RX50)

> On 2/20/19 3:40 PM, Warner Losh wrote:
>> The RX50's are MFM encoded. There's no FM anything on it, unless it's
>> that way on all MFM diskettes.
>> Other DEC diskettes may have done this, but RX50's are just higher track
>> density, but old pre IBM-AT data encoding rate diskettes.
>> At least on the Rainbow the floppy chip is kept in MFM mode all the
>> time, unless you've written something to hack it to read alien disks.

On Wed, 20 Feb 2019, Chuck Guzis via cctalk wrote:
> You're quite correct--I didn't notice the "RX50" until I'd posted.  No,
> I was thinking (as probably was the OP) of RX02 double-density.

That was my mistake.  I wrote RX50, but I meant RX02.
And, as Chuck pointed out, the MFM data within the sectors is not quite 
the same as the MFM encoding used by others.

Sorry about that.

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