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Comment by WalterBright | Hacker News Reader

I lost nearly all of the software I wrote while at Caltech due to the university's magtape drive being out of spec so only that drive could read the tape.

There wasn't any value to it, but I wish I still had it.

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If you still have the tape, you could intentionally hack a drive to make it be the same kinda out of spec.

I was going to say. You don't have to treat these as black boxes. You can even look at the raw magnetic signal and see exactly how it's out of spec

Yes, indeed. This was so common that in studios that for playback of imported stuff on stereo tape you'd switch polarity on one output and then tweak the head for the null. This is more important for wider tapes. For multi-track (not stereo) tape this would be more difficult, picking the track with the highest frequencies on it was usually a good bet. Then you'd aim for maximum output.

We also had special head alignment tapes that would be used just prior to an important recording. Usually this was a single screw, one side of the head would be held fixed in place and the other could be adjusted up or down against a spring, the head would tilt relative to the tape running direction. On very fancy multi track recorders you could also lift the whole head up and down so the (very small) heads would match up with the tracks.

I tossed the magtape decades ago.

I'm also sorry I threw away my punch card decks.

And I'm sorry I sold my H11 for $25.

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