Many thanks for the advice. I am keen to consider all possibilities before starting the transfer marathon.
I like new toys, & I would love to own a RH1/M200, but I simply can't afford one. (None on eBay at the moment!) -Any chance of a loan anyone?
I am still keen to capture the raw ATRAC data stream. I calculate that at the bitrate of 300Kbit/s would give a file size of only 2.2Mbyte per minute, which was the advantage of ATRAC in the first place!
I calculate that capturing the raw data stream from the spdif line (about 3Mbit/s) would give me file sizes of 21Mbyte per minute & no real advantage, so I have ruled that out. I note the factor of 10 'data inflation' of the SPDIF stream compared to ATRAC, so 10 times more hard disc space required for archiving.
I now realise that ATRAC3 codec is NOT backwards compatible, but I am still confused by the statement that there is no software decoder for standard ATRAC on a PC. Surely SonicStage has one, & I seem to remember ffmpeg would also do this?
Without a RH1, I will have to go for a quick-n-dirty approach. I have identified a suitable ATRAC data stream tap-off point on my Sony cct board. I plan to add a TTL buffer, & to dig out an old laptop with a serial I/O port to input this data stream, then worry about software decoding of the captured file. If (when) I reach a dead end & find I have wasted my time, I can always fall back to the SPDIF sound card method.
Please correct me if I have got something else wrong.