Brian Willoughby wrote:

> Could an answer be found by examining the NeXT install CDs at the block level?
> I believe that those are Rockridge - isn't that ISO compatible?

No, they simply have a disklabel and BSD filesystem (with disk and 
filesystem sector size of 2k).

> I may not remember this precisely, but the floppy was only needed on older  
> systems because the firmware would not boot from the 2048 byte block devices  
> -or- perhaps it was because a CD-ROM is identified as a different type of SCSI  
> device, and would normally be ignored as a boot device (just like you cannot  
> boot from a SCSI scanner).  I believe that the newer NeXT's, especially the  
> later Turbo machines, would boot from CD-ROM without the floppy.

Yes, all of these. The older systems needed the floppy bootblock to cope 
with the 2k sectors. Even for the newer system it was more convenient: 
It figured out where on the SCSI chain the CD-ROM drive was, and it also 
  forced the use of the CD for both kernel and root device (easily 
forgotten on the PROM prompt).

Timm