Status of support for 4KB disk sectors

[perryh at pluto.rain.com]

Chuck Swiger <cswiger at mac.com> wrote:
> On Jul 19, 2011, at 2:10 PM, Peter Jeremy wrote:
> > On 2011-Jul-19 10:54:38 -0700, Chuck Swiger <cswiger at mac.com> wrote:
> >> Unix operating systems like SunOS 3 and NEXTSTEP would happily
> >> run with a DEV_BSIZE of 1024 or larger-- they'd boot fine off
> >> of optical media using 2048-byte sectors,
> > 
> > Actually, Sun used customised CD-ROM drives that faked 512-byte
> > sectors to work around their lack of support for anything else.
>
> Hmm-- my brain could be fuzzy about things twenty-plus years
> ago.  But I remember booting a Sun3_35 or _60 from a non-Sun
> or Sun OEM'ed SCSI CD-ROM drive, probably a Plextor?

IIRC, Plextor (and maybe some others) had a switch to select 512 or
2048 as the default transfer size, precisely so that they could be
used as boot devices with systems that supported only 512.