On 2014-11-21 19:48, Jerome H. Fine wrote:
  Michael
Thompson wrote: 
  Where can I get RX01 SSSD 8" floppies?
 Used are fine.
 
 I should have realized that the situation needs to be clarified:
 (a)  As far as I know, (almost?) all soft sectored 8" floppy media
 are formatted as either single-density (which is the IBM standard -
 also known as the DEC RX01 option) or double-density.(which
 is the additional DEC RX02 option).  In the latter case, the format
 is essentially the same, but only the data portion of the sector is
 double-density.  In addition, while a DEC RX01 drive can use only
 single-density media, a DEC RX02 drive can use BOTH single-
 density (SSSD) AND double-density (SSDD) media which means
 that the DEC RX02 drive can read / write media from a DEC RX01
 drive - but can boot an RX01 media only if the boot block is first
 changed from DX to DY. 
 
Incorrect. The RX02 cannot read standard 8" Double Density floppies. It
can only deal with single density floppies, just like the RX01.
The RX02 can deal with both RX01 and RX02 media. However, the software
(obviously) needs to know how to deal with it, as RX02 media gives you
256 bytes per sector, while RX01 media gives you 128 bytes per sector,
which is a significant difference that needs to be dealt with.
(And yes, the software can detect what format each sector is in.)
        Johnny