> On Nov 3, 2022, at 7:38 PM, Fred Cisin via cctalk <[email protected]>
> wrote:
>
> On Thu, 3 Nov 2022, Paul Koning via cctalk wrote:
>> An example of a non-PC format 5.25 inch disk that normal drives can read
>> would be the DEC RX50 floppy, which has 10 sectors per track rather than the
>> PC standard 9 sectors. But a standard drive will read and write those just
>> fine, if it's told to use that format. I did that ages ago in DOS, but in
>> the past 15 years or so I've only used Linux for that job. It's a simple
>> matter, you just need to know what the format is.
>
> 'course MS-DOS/PC-DOS/WINDOWS can't understand anything other than its own
> very limited selection of formats. Does Windoze 11 still understand the
> original 160K format of PC-DOS 1.00?
> ...
> But, with a little programming, such as dropping down to BIOS level, and
> calling INT13h, you can read most others that use IBM/Western Digital sector
> and track structures (generally becaause they used a WD or NEC FDC)
> http://www.xenosoft.com/fmts.html is a list of some of the ones that I
> implemented in XenoCopy-PC
Exactly, and that's what I did way back when, in my original implementation of
"flx" -- a utility for accessing RSTS file systems on a PC. Later I added a
Linux way to do that, which is very much simpler -- just a matter of setting
the right mode, either with the fdprm utility or just by issuing an ioctl. My
current "flx" is written in Python, it does that automatically when it sees a
floppy being accessed.
That version includes a small script to use just the floppy access routines, to
make an image copy of an RX50 either in physical sector order or RX50 logical
order. Look on svn://akdesign.dyndns.org/flx/trunk for the code. "rx50.py" is
that tool; you can also find in "fdprm" the configuration file for the fdprm
utility to tell it about "rx50" format.
paul
