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Comment by chungy | Hacker News Reader

Of particular interest to me is the arcade game Time Traveler, even though by most accounts it is a cheesy FMV game, the technical achievement embraced in MAME is the fascinating bit: the LaserDisc CHD for it is the first of its kind that was dumped by deep signal analysis on the disc and obtaining a level of quality never before seen from a LaserDisc dump; sharp visuals (at least, as far as 480i can be sharp), deep blacks, vibrant colors.

I don't know all the details, but the results speak for themselves. I wholeheartedly believe this should be the present and future standard of LaserDisc preservation.

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If anyone else went "wait, WTF? Surely it can't be..." on reading that post: I checked, and yes, it can.

Wikipedia:

> Although similar in appearance to compact discs or DVDs, early LaserDiscs used analog video stored in the composite domain (having a video bandwidth and resolution approximately equivalent to the 1-inch (25 mm) Type C videotape format) with analog FM stereo sound and PCM digital audio. Later discs used D-2 instead of Type C videotape for mastering. The LaserDisc at its most fundamental level was still recorded as a series of pits and lands much like CDs, DVDs, and even Blu-ray Discs are today. In true digital media the pits, or their edges, directly represent 1s and 0s of a binary digital information stream. On a LaserDisc, the information is encoded as analog frequency modulation and is contained in the lengths and spacing of the pits.

I absolutely thought it was a joke! Thanks for the context!

Any clue it’s possible to read vinyl records this way or are the grooves/material too ill suited for lasers to easily read? Reading deformities of grooves seems like it would require orders of magnitude more precision than the length and spacing of pits, but I know nothing about the physics and hardware here.

Contact-free laser record players exist and have for quite a while, yeah. Main benefit AFAI can tell is avoiding wear on the vinyl.

None are sold to the common consumer or even usable if you had the money [1].

Vinyl wear by using a needle is overstated anyway [2].

[1]: https://youtu.be/2oeTqAogMvA?t=248

[2]: https://www.youtube.com/watch?v=xf_cPU8gtd8

ELP Japan has you covered!

https://www.elpj.com/

Last time I looked into this, I heard it was good if you had a REALLY good record cleaner. It’s extremely sensitive to dust in the groove.

I sort of assumed that Hacker News types would have already known that video on LaserDisc is analog. :)

Audio is somewhat more complicated; the original standards had that as analog too, but digital options were introduced (I'd like to say early 1980s, but not entirely sure).

The first digital audio laserdiscs I bought were in/around 1986. They used AC-3 encoding (later known as Dolby Digital 5.1) but were recorded as an RF signal onto the discs, because the format was analog. You needed a decoder to turn it into discrete channels, which a few receivers had. But most often you would get an external box, like the Yamaha DDP-1

I could never get Dragon's Lair to work with MAME. Going to give that another shot.

I’m not sure if the Dragon’s Lair emulation in Mame ever worked - I think Daphne http://www.daphne-emu.com/site3/index_low.php is the go-to for that one.

Unfortunately the laser disc games didn’t really withstand the test if time between defects in the media and the general failure rates of the consumer quality electronics inside them. Emulation seems to be the only way to enjoy them now. I’ve not seen a working cabinet in many years.

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