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by easyThrowaway 323 days ago
I can't find the link, but there was a Stackoverflow question about ripping a cdrom by using a flatbed scanner, the conclusion was that the scanner would've required 2-3X the DPI currently available on a commercial device to correctly parse the gaps, given that a cdrom laser size is roughly 800nm.

On the other hand I'm still puzzled why there are no homebrew projects for a dumb dumping device that simply reads all the data on a cdrom, error correction, subchannels completely raw. There are a lot of CDs with a very weird data structure (Console Games, Early Copy Protected pc games, AKAI sample discs, some Hybrid Macintosh discs, in other words anything not using the iso9660 standard) which are at risk of Disc Rot[1], and simply storing them as Iso or Bin/Cue files (including proprietary variants like Alcohol 120%/Daemon Tools mdf files) is basically useless both for archival and real world usage purposes.

[1]https://en.wikipedia.org/wiki/Disc_rot
2 comments
ralferoo 323 days ago
> On the other hand I'm still puzzled why there are no homebrew projects for a dumb dumping device that simply reads all the data on a cdrom, error correction, subchannels completely raw.

I think you'd have to write a custom firmware for one specific drive for that. That information is simply not exposed outside the device itself on standard drives, which is what makes it effective for copy protection.

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easyThrowaway 322 days ago
I am no electrical engineer, but I believe most drives still available on the market use an ASIC for this kind of low-level commands.

A more pragmatic solution would be to use an ESP32 or an RPI2040, wire them to a "donor" cd drive and then implement just the most basic MMC commands to make sense of the disc layout and save to disk the binary stream.

I'm pretty sure I'm missing something extremely obvious given the lack of similar attempts; wouldn't be surprised if not a single readily available programmable microcontroller on the market has the necessary bandwidth for this task.

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lathiat 322 days ago
I'd say this project is the closest: https://github.com/superg/redumper

But is not a true raw dump like we see in a bunch of other media preservation projects.

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