brianw@sounds.wa.com (Brian Willoughby) writes:
>I am the author of sdformat, a replacement for NeXT's sdform, which allows a  
>drive to be reformatted with 1024 byte blocks at the low level.  It actually  
>required manual user intervention to obtain 1024 byte blocks.  The main  
>incentive for doing this was so that the low level block access matched the  
>higher level file system allocation unit size.

I can only speak for me and my friends, but back then we reformatted the
Seagates with 1K sectors so that we could squeeze a couple more MB out of
the drive.

>NeXTSTEP for Intel processors did not support this, because the BIOS could not  
>boot from anything but 512 byte blocks devices.  Sun SPARCstation machines  
>running NEXTSTEP or OPENSTEP also could not boot from 512 byte blocks devices.   
>The Sun can handle additional drives besides the boot drive as 1024 byte  
>blocks, and I believe Intel could, too.  The strange thing is that all machines  
>need to boot from 2048 byte block CD-ROM, so I don't see why there was a  
>limitation for other devices to have 512 byte blocks.

Actually, the Sun machines would only boot from CD-ROMs that were in
512 byte logical sector mode and the PROM wouldn't change the logical sector
size of the drive.  That's why you couldn't only use certain drives that
came up in 512 byte sector mode by default or by setting a jumper.

--chris