A file - not an audio track.
From multi-session audio CD - not a CD-ROM.
Disc isn't healthy, and ordinary file system copy commands fail. File isn't something anyone's life depends upon, but I'd like to get out as much as possible.
* For the lack of something better, I am using bbcopy: http://alter.org.ua/soft/win/bb_recover/ . Any other suggestion would be welcome.
* I can set block size. Should I use [a multiple of] anything in particular? 588? Or? Is it drive-dependent?
* For the lack of something better, I am using bbcopy: http://alter.org.ua/soft/win/bb_recover/ . Any other suggestion would be welcome.
What mode is the data track? If it's mode 2, you may have better luck reading an image of the disc (e.g. with ImgBurn) and then extracting the file from the image (e.g. with CDMage).
If you really want to get as much of that file as possible, you might try using the swap trick (https://en.wikipedia.org/wiki/GD-ROM) to read your disc as audio, then offset-correct and descramble the data. It requires a drive that's willing to play along with the swap trick, but it may work better if the drive is more willing to read through errors on audio tracks than data tracks.
* I can set block size. Should I use [a multiple of] anything in particular? 588? Or? Is it drive-dependent?
Assuming this CD isn't particularly exotic, you should use 2048.
I've been playing with ddrescue on my linux box, you can try booting some live ubuntu, installing ddescue and RTFM, there are nice examples online. It has an option to mark unreadable sectors, you can transfer the disc into another drive and load the map and try ripping it from there. The recovery lasts some time, though.
@Octocontrabass :
ImgBurn quickly goes "Operation Failed!", so ... nopes. Swap trick looks funny, will see if I am that desperate. Actually, both 2352 (4x588, which I had initially set it to do overnight) and 2048 got out the vast majority. Trying a different CD drive now.
@itisljar :
I initially assumed that it wouldn't make much difference using this or ddrescue or dd_rescue, as the medium is the same no matter how it is read (as opposed to when I had a dying hard drive that would switch off every ten seconds - fifteen when wrapped in cooling packs - and choice of utility mattered).
But come to think of it: a Linux rescue CD booted to RAM, will use different drivers, so why not.