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A tool for burning visible pictures on a compact disc surface (2022)

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Re: A tool for burning visible pictures on a compact disc surface (2022)

#41

Post by chaboud »

4rt wrote: post #37
m-s-y wrote: post #20

Earlier quoted context omitted.

Same. I had one of these in ‘98/‘99. The disc didn’t even go into a standard tray—-you had to use a caddy that completely enveloped the disc.

any idea what the caddy did? some sort of feedback for rotation angle maybe?

The caddies were just a simple loading mechanism, with a spring door like a floppy disc. I suspect they had the life they did because someone was hoping that we would all buy ultra-expensive caddies for our collections instead of moving discs in and out of cases.

Re: A tool for burning visible pictures on a compact disc surface (2022)

#42

Post by [deleted] »

4rt wrote: post #37
m-s-y wrote: post #20

Earlier quoted context omitted.

Same. I had one of these in ‘98/‘99. The disc didn’t even go into a standard tray—-you had to use a caddy that completely enveloped the disc.

any idea what the caddy did? some sort of feedback for rotation angle maybe?

[deleted]

Re: A tool for burning visible pictures on a compact disc surface (2022)

#43

Post by ungawatkt »

I gave this a go about 3 years ago when the hackday project[1] first got published, it turns out choosing the parameters is _very_ disc dependent, since every disc is a little bit different (possibly even between lots of the same type, not published anywhere, and quite sensitive. I got it working for the CD-R's I got, but it took ~50 experiments to get ok parameters (the image was pretty good, but still wobbly in some areas of the disc).

That said, the end result is pretty cool, if hard to photograph.

[1] https://hackaday.io/project/186303-burning-pictures-on-a-com...

Re: A tool for burning visible pictures on a compact disc surface (2022)

#46

Post by yaky »

gambiting wrote: post #21
Molitor5901 wrote: post #10

I fondly remember LightScribe, that was a pretty awesome technology.

I was going to say, I still have a 5 pack of Lightscribe DVDs unopened in a box specifically to save something "special" but obviously nothing has ever been special enough to warrant using them. And now that they aren't made anymore it would feel downright sacrilegious to use them, not to mention 4.7GB of capacity is just not enough for anything nowadays really.

4.7GB is quite enough for a standalone Linux DVD (for devices that still have DVD drives). Plus some cool art.

Might be a good idea to preserve a known-working distro for some old PC, especially for discontinued or less-used architectures. Just saw a discussion the other day about finding 32-bit Debian for an old laptop.

Re: A tool for burning visible pictures on a compact disc surface (2022)

#47

Post by duskwuff »

4rt wrote: post #37
m-s-y wrote: post #20

Earlier quoted context omitted.

Same. I had one of these in ‘98/‘99. The disc didn’t even go into a standard tray—-you had to use a caddy that completely enveloped the disc.

any idea what the caddy did? some sort of feedback for rotation angle maybe?

Caddies were fairly common in early CD-ROM drives. Tray-loading (and, even later, slot-loading) drives were a later development.

One theory I've seen is that caddies were developed in part to protect valuable data CDs from accidental damage, and faded in popularity as software became more affordable. Early multimedia software could be quite expensive, with some titles running into the hundreds of dollars.

Re: A tool for burning visible pictures on a compact disc surface (2022)

#49

Post by londons_explore »

lucianbr wrote: post #35
londons_explore wrote: post #34

Congrats to the author - a few decades ago I attempted the same, with very little success (using data tracks, not audio, which might have been my mistake). The challenge (as I saw it) was that the drive has the option to toggle the state of the laser every sector, effectively letting it invert all your data if it wants to. To have control of the laser state, you need to be able to do perfect predictions if the drive…

Assuming control of the decision to toggle, could that be used to draw something even while burning useful data? Of course you would have very low precision, but still. Maybe an outline or something.

Yes. You get the option to toggle the laser every 33 bytes, which is a lot of controllable toggles to make cool patterns.
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