Years ago when I worked at an audio store, a guy brought in a 'used' pulse code modulator. We figured it was obviously stolen but we took it as trade-in anyways for $200.

It was a Sony PCM-701ES and the way it worked was you hooked it up to any VCR (even a mono one) and it used the video track to record a digital signal in stereo at either 14 or 16 bit. It worked great so I bought it for myself. (still have it)
And for sure, it works amazingly. I've still got old Beta tapes from the studio back in 1993 that are as good as new. At one point I took all my old CD's and recorded them onto video tape as digital so I could get 6 hours of music on each tape. Course, then new technology came along and screwed everything up.

Anyways, I used to use the PCM to take 4 tracks of audio from the fostex, and mix it down to stereo, then use the extra 2 tracks for vocals.

It's outdated now, but I still keep it around.