This dredged up a question I had two decades ago and never looked up. Perhaps someone here knows. I got to use a Tascam DA-38 a few times. It was an 8 track and I could have sworn it had punch-in recording. It used DTRS, not DAT, but apparently it shared the helical scan. Presumably the 8 tracks were interleaved on a single bitstream, so how was it possible to seamlessly replace one track live? Was there more than on…
I've checked an SoS review [0], and it seems like it was a multi-head operation (although I don't know if that's what enables the track punching): > The ability to monitor off tape during recording is due to the DA38's 4‑head drum layout. -- 0: https://www.soundonsound.com/reviews/tascam-da38
This SoS article doesn't answer it, but provides more background.
https://www.soundonsound.com/sound-advice/all-about-digital-...