Xref: utzoo comp.sys.amiga:17618 comp.sys.amiga.tech:290 Newsgroups: comp.sys.amiga,comp.sys.amiga.tech Path: utzoo!utgpu!jarvis.csri.toronto.edu!hub.toronto.edu!lemke From: lemke@hub.toronto.edu (R Lemke) Subject: Re: Getting a Mac Hyperdrive to work with a A2090 Message-ID: <8804101928.AA15294@hub.toronto.edu> Organization: University of Toronto Date: Sun, 10 Apr 88 13:28:00 EDT In article <831@sdcc8.ucsd.EDU> cs178abu@sdcc8.ucsd.edu.UUCP (John Schultz) writes: >In article <759@elxsi.UUCP> matt@elxsi.UUCP (Matt Shaver) writes: >>As far as I can tell the drive physically has: >> 4 heads >> 26 sectors per track >> 818 cylinders >> > We just installed a 2090 with an ST251 in our 2000 as: > 6 Surfaces > 17 BlocksPerTrack > Total cylinders 0-819, or 820 > > It's partioned as four 10M partions, ~205 cylinders per part. The >last partion is short because of AmigaDos' use of the first two >cylinders. > Anyway, the drive (knock on wood) works perfectly. As far as I >know, the only differences between the 251, 251-1,251N are seek >speed and/or interface (251-1: 28ms, 251N SCSI). > > So, change the number of heads to 6... That should fix it. > > > John I have just recently installed an ST251N in my B2000 and discovered the the 251, 251R and 251N are *not* the same physical configuration. According to the booklet that comes with the drive: drive capacity heads cylinders max-blocks 251 42M 6 820 ? 251R 43M 4 820 ? 251N 43M ? ? 84,254 At first, I assumed that the 4 heads number was a typo. My final opinion though, is that the 251 has 6 heads and is formatted with 17 sectors per track; while the 251R and 251N each have 4 heads and are formatted with 26 sectors per track. Further, the max-blocks number for the 251N is about 10% smaller than 4 * 820 * 26, to allow for remapping of bad blocks. Format seems to hang when trying to format more than 84,254 blocks. I hope this info helps answer some nagging questions. It is the best that I could figure out. (Wouldn't it be nice if Seagate would just tell us what all the parameters are?) Jim -- Jim Lemke CSRI, University of Toronto, Ontario, Canada UUCP: {decvax,ihnp4,linus,utzoo,uw-beaver}!utcsri!uthub!lemke CSNET: lemke@hub.toronto.edu CDNNET: lemke@hub.toronto.cdn BITNET: lemke@hub.utoronto -- -- Jim Lemke CSRI, University of Toronto, Ontario, Canada UUCP: {decvax,ihnp4,linus,utzoo,uw-beaver}!utcsri!uthub!lemke CSNET: lemke@hub.toronto.edu