The last VHS machines

[Murphyv310]

 If you knocked an MD machine when recording, that would send the laser off in the wrong direction, and if the TOC failed to write, that would trash the entire disc.

Hi.
In fact doing that wont trash a disc.
Here is the way we did it in Sony.
But a blank disc in the recorder and record for the full length minus 30 seconds, at the point of 30 seconds before the end of the disc remove the power. Unwind the mechanism and remove the disc, Insert the "trashed" disc and manually wind the disc in till fully in with the over-write head in the "record" position. power up and press eject, this will write one continuous track to the disc. You can then read back in a continuous stream what is on the disc. The disc will then be usable for new recordings by erasing the TOC and will then be a normal blank disc.