plummer@hercules.cs.uregina.ca (Dave Plummer) (05/15/91)
I'm having some trouble trying to figure out how the hard drive geometry is represented. My ST157N drive _should_ have 94860 blocks. That's 94548 data + 2 reserved + 310 reserved for HardBlocks. That it does. If you look at the aparrent SCSI geometry, that's 155 * 612 cylinders. That's what I expected. Now the question: what kind of drive has 155 sectors per track? That's _not_ 0-155, that's 155 per track. Is one reserved by SCSI as a spare? Is that a function of the drive or the A2091? How do you determine if/how many are set aside? Is it always one? Could this be what the rdb_CylBlocks field represents?
rick@tmi.com (05/24/91)
In article <467@regina.uregina.ca>, plummer@hercules.cs.uregina.ca (Dave Plummer) writes: > I'm having some trouble trying to figure out how the hard drive geometry > is represented. My ST157N drive _should_ have 94860 blocks. That's > 94548 data + 2 reserved + 310 reserved for HardBlocks. That it does. > > If you look at the aparrent SCSI geometry, that's 155 * 612 cylinders. > That's what I expected. Now the question: what kind of drive has 155 > sectors per track? That's _not_ 0-155, that's 155 per track. Is one > reserved by SCSI as a spare? Is that a function of the drive or the > A2091? How do you determine if/how many are set aside? Is it always > one? > > Could this be what the rdb_CylBlocks field represents? According to one of my lists, the ST-157N and ST-157N-1 have the following geometry: Form Factor: 3.5" Capacity: 48MB Cylinders: 613 Heads: 6 Sectors/Track: 26 Encoding: RLL Max. XFer.: 10MB/S (Sure. Uh huh! Right. I believe that. 8-) Seek Time: 40ms (157N), 28ms (157N-1) I hope that helps. As to how they determined a maximum transfer rate of 10MB/s, I have no idea. .--------------------------------------------------------------------------. |[- O] Rick Stevens | | ? EMail: uunet!zardoz!tmiuv0!rick -or- uunet!zardoz!xyclone!sysop | | V (rick@tmi.com) (sysop@ssssc.com) | | CIS: 75006,1355 (75006.1355@compuserve.com from Internet) | | | | "If it's stupid and it works, it ain't stupid!" | `--------------------------------------------------------------------------'