Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!xstor!iverson From: iverson@xstor.com (Tim Iverson) Newsgroups: comp.sys.ibm.pc.hardware Subject: Re: SCSI confusions, help please! Message-ID: <1991May24.235137.13807@xstor.com> Date: 24 May 91 23:51:37 GMT References: <1991May20.221754.1226@always.com> Reply-To: iverson@xstor.com Organization: Storage Dimensions, Inc. Lines: 60 In article <1991May20.221754.1226@always.com> rick@always.com (Rick Wagner) writes: >In article tims@infidel.lanl.gov (Tim Sullivan) writes: >> ... So, for less than double the price of an MFM >>hard drive of comparable size, we can switch to SCSI and have the >>occasional use of the big disk and tape drive. At an (off-the-cuff) guess, SCSI should only be about 10% more. Less than double sounds like you're being rooked. >This may not be as easy as it seems. I beleave that the Sun formats >the SCSI drive to 1024 byte sectors, while DOS will want 512 byte >sectors. The Exabyte shouldn't be a problem though. You're right that it won't be easy, but not because of the sector size. Sun systems use a 512 byte sector format, just like DOS and the various PC Unixes. The problem is the partition table. A Sun label (what Sun calls their partition table) is placed on lba 0. A DOS/Unix partition table (what IBM calls their label) also gets placed on lba 0. They are not compatible. If you don't mind re-labeling and mkfs'ing (Sun) and repartitioning and formatting (DOS) every time you move the drive back and forth, then you can share the drive without any special software. If you don't want to do this, you'll have to write a driver that allows one of your two OSes to talk to a drive formatted for the other. Or, you could use PC-NFS. The Exabyte may be a problem under DOS - you'll need software from someone that will allow you to access it; DOS can't do it alone. In fact, most ISA host adapters do not come with software to do this. You'll have to shop for it. >>I've heard that you should buy the SCSI controller from the same >>people you buy the disk from, so I looked in the R-Squared catalog and Try it before you buy it - get an eval set or if they won't do that, then ask them to come out and demo or go see one somewhere, or (well, you get the picture). >>sure enough, they sell a SCSI controller to attach their drive to an >>AT for $1600! And a 91 Mbyte, internal hard drive for $1725! Wow. For that price, it better be a real special system. For a 100MB scsi subsystem, I would guess $500 (we sell them, but you'll have to talk to a salesman to get the real story). >>So what is wrong here? What is it about SCSI controllers that can >>support price differences so large? What does a $1600 controller do >>that a $100 controller doesn't do? Hellifino (the small pink kind found in whiskey jars ... :-). Give 'em a call and ask. Could be that they do something so nifty it would be a bargain at twice that, but it would have to be something truly awesome. >>Tim Sullivan (tims@goshawk.lanl.gov) >Rick Wagner / Always Technology email: rick@always.COM - Tim Iverson iverson@xstor.com -/- uunet!xstor!iverson