Thanks for the info, GoogleTranslate picked-up most of your original post so I got the idea from that. I'm not too sure about re-working the codec but the concept of playing audio from a floppy-disk shouldn't be too hard (if you can still get the media!). I have a selection of HD and ED disks in the attic which I will look for at the weekend and perhaps we can arrange to have a couple sent out to you?
I don't have a spec on the RS232 but I have just pulled the brochure from my files and it says: "RS232 for remote control and transmission logging". The troubling issue with these machines is that Mitsumi+Sony stopped making the ED (4MB) drives in 1999 which means if a drive fails, you will need to use a spare machine for parts or have a "dead" slot in the triple-stack. I am not sure what happens if you replace them all with HD drives and just use them for short jingles, it should work in theory. A similar machine, made by ASC and called the DART also used HD/ED disks but in later years they offered a magneto-optical (230MB, I think) drive to upgrade the units making them very similar to MiniDisc in terms of storage vs size etc. Click here, and scroll down a bit to see an example of a Play+Record unit:
http://www.devcountyradio.freeuk.com/radio_kit2.htmI took a phone picture of the Discart specs, sorry it's not a scan but I'm on my laptop:
http://www.charliedavy.co.uk/sonifex_discart_specs.jpg The brochure doesn't really go into technical terms other than record duration vs sample-rates and basic marketing jargon.
Something I did have from my notes, is the remote-start pin-outs:
Pin 1 0v (common)
Pin 2 play 1 switch (momentary make to common)
Pin 3 play 1 lamp
Pin 4 play 2 switch (momentary make to common)
Pin 5 play 2 lamp
Pin 6 play 3 switch (momentary make to common)
Pin 7 play 3 lamp
Pin 8 Recue switch (momentary make to common)
Pin 9 Recue lamp
Pin 10 Record Tally (Open collector 40ma sink in record)
Pin 11 Studio on line
Pin 12 Select Switch (momentary make to common)
Pin 13 Cue Output
Pin 14 Cue Output
Pin 15 Cue Output