(Not quite cd/dvd/bluray, but definitely related at a very low level).
“Introduction to Abstract Algebra” 2nd ed by W. Keith Nicholson.
I was mainly interested in the chapters on error-correction codes from this textbook and the mathematical theory underlying it. This book appears to be for an introductory university level course on algebraic structures (ie. groups, rings, fields, etc …).
If you’ve been following some of the threads I’ve been posting on here, I’ve been examining error correction codes on dvds.
Picked up a recertified WD 2TB for €45 directly from Western Digital, which arrived in a large well-padded shoebox size box. I mainly plan using it for carrying bulky files, so am not overly concerned about its reliability being recertified. For anyone that hasn’t seen a modern 2.5" USB HDD or only used DIY 2.5" HDD enclosure kits, these are quite compact. This makes my 5.5" phone look huge.
From what I recall reading, recertified drives are quite often barely used drives that were returned as open boxed goods. In the case of USB powered HDDs, often it’s people unaware that many front PC and some laptop USB ports don’t provide enough power to spin up the drive, resulting in the user RMA’ing the drive as defective / DOA.
Indeed CrystalDiskInfo shows a “Power on Hours” count of zero and just 3 power-up cycles, assuming WD didn’t reset these.
CrystalDiskInfo figures are typical for this type of drive, although interesting to see identical sequential read and write speeds.
Today shopping groceries I happened to see definitive cleaning of optical media stocks - last pieces of very dusty 10-pk cakes of TDK media was sold for ~2€ independently of media type. I bought 2 cakes each of DVD-R MIT (Ritek F1), DVD+R MIT (Ritek F16) and DVD+R DL MII (MBIPG101-R10-065). Only the last ones seem to be a kind of bargain, but I’m curious how other ~2010 discs will perform.
I bought these BD-R discs from two different sellers, both batches are with VERBATIMa codes (haven’t opened each of them, but externally all the boxes are identical, so I assume that they are all same). Actually I was hoping for own Maxell codes (have seem them listed in FW dump of early LG drives), but at least burn quality is decent
My batches of Maxell BR2 burn better than Panasonic MEIRA1 on my iHBS112 clone (PX-LB950SA), initial scans can be seen here: 1, 2,
Having in mind their terrible reputation in terms of longevity I use them only as redundant medium for data that I stored already somewhere else. Since I’m fairly fresh to BD-R, my oldest Maxell BR2 is only 11 months old, but so far no single signs of longevity issues (I store discs in cakes, so it’s not always easy to ensure 100% dust free surface for repeated scan, but I will post it soon). Maybe Ritek took the lesson?
I assume that every company doesn’t want to be dependent on one supplier (i.e. Ritek only) and they seek alternative ones, just consider never ending discussions about origin of Verbatim branded media. Just make sure you get a good batch