cjroehrig@poppy.uwaterloo.ca (Chris J. Roehrig) (07/29/90)
Our lab bought a Maxtor XT-8760S 660MB hard drive to install in our NeXT. It seems to work fine, but only gives 620MB or so. This is partly because it was formatted for 512 byte sectors 54 sectors per track 5 spare sectors per cylinder instead of 1024 byte sectors 28 sectors per track 4 spare sectors per cylinder which is what the NeXT is shipped with (obtained using /usr/etc/scsimodes). You'd expect 512 byte sectors to give twice as many sectors/track as 1024 byte sectors, but there is only 54 sectors instead of the 56, so 1K/track is 'lost' which accounts for 24.5 MB. The drive has 639 MB of usable sectors on the volume. I suspect the rest is lost due to using a poor disktab entry (Builddisk used the stock XT-8760S-512 entry which doesn't quite correspond to my drive geometry; e.g. it says 1 spare sector/track -- my drive has 5). I'd try to write my own, but I have no idea where the partition sizes come from (e.g. how to choose them to avoid wasted space). So: I'd like to do a low-level reformat of the drive with a 1024 byte sector size and 28 sectors per track to get it up to 660MB, and use the proper disktab entry, but the NeXT doesn't come with a format program. I have TheFormatter from j.cc.purdue.edu, but it seems to be only for Wren drives. Are there any general SCSI reformatters for the NeXT out there? Alternatively, if a Sun reformats the drive, would it still work on the NeXT? Are the SCSI controllers compatible? (The NeXT has an NCR 53C90 SCSI controller chip.) I'd sure hate to try it and not have a usable drive. Thanks for any info, Chris Roehrig Audio Research Group, University of Waterloo, Canada