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Interesting! Does anyone know of a language or operating system that uses Reed–Solomon error correction on every file? https://en.wikipedia.org/wiki/Reed–Solo

Interesting! Does anyone know of a language or operating system that uses Reed–Solomon error correction on every file? https://en.wikipedia.org/wiki/Reed–Solomon_error_correction https://en.wikipedia.org/wiki/Reed–Solomon_error_correction Or to top that, imagine a computer where the entire memory space, perhaps shared with persistent flash memory, was encoded in this manner, so that even the filesystem was protected against bit flips. When I was doing Mac repair a few years back, the majority of the PowerMac G5s that came through the doors died premature deaths for two reasons: the ram was in a bad spot which caused the board to bend and crack on insertion, and the ram was non-ECC so it was notoriously difficult to isolate a bad ram chip. It was the most unreliable Mac I ever diagnosed, by perhaps an order of magnitude. Contrast that with the Mac Pro, which used ECC and was so much more reliable that I don't remember seeing a single Mac Pro fail in the 3 years I was there. Imagine how stable a Reed–Solomon computer would be..

CraigJPerry 13y ago
ZFS (the file system) goes to some fairly extreme lengths to validate data. It effectively doesn't trust anything past the south bridge.
usefulcat 13y ago
> Does anyone know of a language or operating system that uses Reed–Solomon error correction on every file? A while back, after losing some personal photographs to bit rot, I became curious about this and did some experimentation with RS. The biggest drawback I found was that even with a relatively fast processor it is slow compared to typical disk read/write speeds. I concluded that the ZFS approach of RAID + checksums would be preferable.
MaysonL 13y ago
In the early 1970's I implemented the driver for, and programs using, a digital videotape drive (IIRC, it incorporated an Ampex 2 inch reel-to-reel recorder, and used the sound track for positioning information). It used hardware Reed-Solomon error correction (IIRC, it was capable of correcting up to 11-bit errors). It stored a massive (for the time) database of scanned drawings for a number of aircraft maintenance manuals.
Tomte 13y ago
In safety-related system you usually don't try to correct bit flips (at least in my niche), but you've got lots and lots of mechanisms ensuring that bit flips are discovered. Even more, hardware faults like stuck-at bits and so on need to be discovered, as well. The downside is that all those checks are slow.
- jmpe 13y ago
  For more info on this search for "defensive programming", "Immunity-aware programming" and "preventitive programming". Several hardware companies have manuals/rules for programming in harsh environments. Even if you're not into hardware it's worth a look, lots of cool tips.

CraigJPerry 13y ago

ZFS (the file system) goes to some fairly extreme lengths to validate data. It effectively doesn't trust anything past the south bridge.

usefulcat 13y ago

> Does anyone know of a language or operating system that uses Reed–Solomon error correction on every file? A while back, after losing some personal photographs to bit rot, I became curious about this and did some experimentation with RS. The biggest drawback I found was that even with a relatively fast processor it is slow compared to typical disk read/write speeds. I concluded that the ZFS approach of RAID + checksums would be preferable.

MaysonL 13y ago

In the early 1970's I implemented the driver for, and programs using, a digital videotape drive (IIRC, it incorporated an Ampex 2 inch reel-to-reel recorder, and used the sound track for positioning information). It used hardware Reed-Solomon error correction (IIRC, it was capable of correcting up to 11-bit errors). It stored a massive (for the time) database of scanned drawings for a number of aircraft maintenance manuals.

Tomte 13y ago

In safety-related system you usually don't try to correct bit flips (at least in my niche), but you've got lots and lots of mechanisms ensuring that bit flips are discovered. Even more, hardware faults like stuck-at bits and so on need to be discovered, as well. The downside is that all those checks are slow.

jmpe 13y ago
For more info on this search for "defensive programming", "Immunity-aware programming" and "preventitive programming". Several hardware companies have manuals/rules for programming in harsh environments. Even if you're not into hardware it's worth a look, lots of cool tips.