dumb rx01 image question

Don> The 'even/odd-skew-by-6' algorithm mentioned in a previous email Don> is what I found works for XXDP. It is probably the DEC Don> 'standard' for RX01/02 drivers. I would assume that is the case. I found it in a RSTS driver, and the that that two very different systems share a mapping function suggests it's a DEC standard. (DEC certainly tended to standardize this sort of thing company-wide.) FWIW, RX50s are interleaved and skewed, too. The track length is 10 so the groups are logical sectors 0-4 and 5-9. Also, the first group is the odd one (so logical sector 0 is physical sector 1). Track skew is two sectors, bnot 6. Finally and most strangely, while on RX01 track 0 is unused, it isn't on RX50. What happens instead is that it's the last track. So logical block 0 is track 1, sector 1, and logical block 799 is track 0, sector 4. Go figure... paul