21 Nov
2014
21 Nov
'14
4:28 p.m.
On 2014-11-21 12:44, tony duell wrote:
I seem to remember that if you format an 8" floppy, single sided, single density
'IBM3740 format' (the standard one, 77 tracks, 26 sectors/track, 128
bytes/sector)
then at least an RX02, and probably an RX01 can be convinced to put the DEC
type directory, etc. on it. An RX02 can re-format it as MMFM too.
Of course. You don't even need to do any convincing. A directory (which
differs between different OSes) can always be written. That is just
bytes of data on the floppy.
Is it correct that RX01 format floppies can be
created from blank
floppies with a standard PC floppy controller (or at least some
controllers / motherboards, depending on the controller chip) while
RX02 format floppies cannot?
Yup. The RX02 ("double density") use a whacky MFM scheme (with some
code substitutions) for data with FM sector headers. Not doable at all
with a standard PC setup. RX01s are pretty much stock FM. Most CP/M machines with 8" drives can do the
intial format
I should probably point out that an RX01 or RX02 cannot actually format
floppies at all. They need preformatted floppies, in the IBM format.
Johnny