4 ms·
Not too bad. I was expecting the first shaving step to be about the OS media requiring 520 byte sectors and thus needing a "fancier" CD writer/reader. Maybe tha
by puzzle 8y ago
Not too bad. I was expecting the first shaving step to be about the OS media requiring 520 byte sectors and thus needing a "fancier" CD writer/reader. Maybe that was Sun, not SGI?
- classichasclass 8y agoYou might be thinking of OS/400 aka IBM i, which indeed uses 520 byte sectors. Sun used 512.
- puzzle 8y agoYeah, I know about OS/400 using the extra bytes on hard drives for the pointer tags (not a checksum), but what I had in mind were data CDs, whose canonical sector size was 2048.
- octorian 8y agoI think the whole 512 byte sector CD-ROM thing was common to all the 90's-era "Real UNIX" machines. They generally all wanted to treat CDs like a hard drive, for booting purposes. (PCs, on the other hand, did a different weird hack where they'd embed a floppy image at the state of the CD and the BIOS knew how to handle that.)
- puzzle 8y agoYeah, you're right, they wanted 512 instead of 2048 bytes per sector to use the CD as a HD. But I think that at least one of the Unix vendors shipped the install media as 520 byte sectors, with 512 bytes of data and 8 bytes of checksum. In order to duplicate the discs, you needed to own a writer that was fancier than average (i.e. a SCSI unit, not an IDE one).
- __d 8y agoI keep a DEC RRD-40 drive (with its weird pre-caddy disc holder thing) around for the purpose of booting old DECstations. Not sure if it used 520B sectors though. I think I have the manual .. somewhere.
- linksnapzz 8y agoAFAIK, the "El Torito" standard, so named for the restaurant where ppl. from IBM & Phoenix BIOS hashed out how to do it...
- Taniwha 8y agoI'm pretty sure it was apple who used 520 byte sectors, first on floppies, but also on Earl hard drives too