Hubert - I believe that the SX-1 machines have supported the Sony P2 remote control protocol ever since the 1.5 version of the OS came out (from past discussion I think your machines are using 1.52) I suspect that Tascam's RC-828 Remote Controller also uses that protocol even though they were originally introduced for remote controlling the DA-38 and DA-98 Digital recorders (they used the Hi-8 Video Cassette recording media). I have seen the RC-828 on eBay for about $80.00 but CANNOT confirm that it is P2 protocol compliant - it could be it uses a Tascam protocol the predates the P2 protocol used by the SX-1. IF is P2 compliant, then a cable that connects it to the SX-1 is all that I think you would need. Maybe someone who is familiar with the DA-98 can verify what protocol it used for remote control. I did find a software product that is a software implemented P2 Protocol Remote control for VTRs that looks like it runs soon Windows PCs. That might provide you with transport control via RS-422 9-pin cable. It can be found by searching for Sourceforge Sony RS-422 VTR Controller. All this stuff is legacy - circa 2005.
If you have some solid electronics experience, you could use a shield cable (via connector you would have to add to the SX-1) to parallel the transport buttons on the from panel of the SX-1 and run it to a duplicate set of pushbutton switches but this would take a lot of work and could be risky!
Probably cheaper to just buy a portable 8 channel machine like a Zoom R16 and transfer the files to your computer and then from it to the SX-1 in FTP mode using the ethernet connection. Plus you get a nice compact stand alone location recorder.
