sigma@picasso.ipl.rpi.edu (Kevin Martin) (05/03/91)
I recently got my new system set up. I have a 386/25 non-cache 4Mb system with a Conner 212Mb IDE drive. Works like a charm. 1) How does IDE *really* handle bad sectors? There is no defect list, no defects turned up during high-level formatting or partitioning, but this morning trying to unzip a file led to about a fifteen-second pause with the drive light on, several long seeks, and then the read succeeded, but PKUnzip didn't understand the file. I deleted it. DiskFix from PCTools was unable to find anything wrong with the disk. Am I right in surmising that the drive found the error, and when it couldn't correct it, simply mapped in a sector from a reserve somewhere and returned a blank sector of data? What happens when the reserve runs out? 2) What *is* the difference between the CP-3204 and the CP-3204F. My documentation only mentions the 3204, but this is labelled as a 3204F. It's impressively fast, CoreTest 2.92 returns 1123.4 Kb/sec transfer and 16.2 ms average seek. Anyone with a similar setup and a 3204 want to compare notes? Thanks, -- Kevin Martin sigma@ipl.rpi.edu "I am NOT a Merry Man!"
sigma@picasso.ipl.rpi.edu (Kevin Martin) (05/03/91)
sigma@picasso.ipl.rpi.edu (Kevin Martin) writes: >I recently got my new system set up. I have a 386/25 non-cache 4Mb system >with a Conner 212Mb IDE drive. Works like a charm. I've had a few answers on these. 1) About PKZip pausing during processing - I assumed the drive was fixing a defect. Come to think of it, the file was probably bad in the first place and PKZip was scanning for a valid directory within it. 2) CoreTest isn't a great test of disk transfer rates, I'm told. Well, CheckIt! reports roughly 500 Kb/sec, half what CoreTest said. But why should it be any more sure? Neither program turns off the drive's internal cache, I'd bet. And the cache is always there, too. But my point is just that I wanted to know the difference between CP-3204 and CP-3204F. Benchmarks or otherwise. -- Kevin Martin sigma@ipl.rpi.edu "Can I kiss one of the bridesmaids instead?"
mort@hpihoah.cup.hp.com (Mark Mortarotti) (05/11/91)
I hate to be the one to tell you this, but as I understand things related to IDE disk drives, all IDE drives come pre - formated from the factory. Using any low level format program on them including the DM program from Seagate will mess up the drive. I don't understand what the issue is, or why there could be a problem, just that the manufacture is using a proprietary routine for the purpose. As for what it does or does not do is unknown. The bottom line message I have for you is: DON'T low level format your disk. If you have and are starting to see problems (bad sectors/tracks) you should go back to the place of purchase, and exchange it for another disk (assuming that they did not tell you not to low level format your disk). If you noticed, the disk drive did not come with any initializing disk, right? Gook luck mark
dd2x+@andrew.cmu.edu (David Eugene Dwiggins) (05/14/91)
First: IDE Drives are VERY different. Statements like "IDE offers better performance than MFM and ESDI" are false simply because some IDE drives use MFM encoding, some use RLL, etc. As for formatting IDE drives, some do _NOT_ come preformatted from the factory. They usually have a formatting utility in ROM if they don't, but there's no reason why the MFM ones couldn't be formatted with an MFM utility. And it's _NOT_ destructive (at least to the drive) to use a formatting utility on some IDE drives. I glitched the boot sector in my Quantum and FDISK refused to format the drive. I called Quantum and they said there was no way for me to low level format the drive, and to use anything to clean it. STOP making generalizations about IDE drives. They're as diverse as people, i.e. "People like broccoil" is obviously false. David
phil@ux1.cso.uiuc.edu (Phil Howard KA9WGN) (05/14/91)
dd2x+@andrew.cmu.edu (David Eugene Dwiggins) writes: >First: >IDE Drives are VERY different. Statements like "IDE offers better performance >than MFM and ESDI" are false simply because some IDE drives use MFM encoding, >some use RLL, etc. How does one tell the difference? And how many different encoding systems, or other things, are relevant? Is ESDI its own encoding system? -- /***************************************************************************\ / Phil Howard -- KA9WGN -- phil@ux1.cso.uiuc.edu | Guns don't aim guns at \ \ Lietuva laisva -- Brivu Latviju -- Eesti vabaks | people; CRIMINALS do!! / \***************************************************************************/
carl@caicos.cayman (Carl Heinzl) (05/17/91)
>>IDE Drives are VERY different. Statements like "IDE offers better performance >>than MFM and ESDI" are false simply because some IDE drives use MFM encoding, >>some use RLL, etc. >How does one tell the difference? Don't know, sorry... >And how many different encoding systems, or other things, are relevant? >Is ESDI its own encoding system? No, ESDI is a difference in the interface. Every ESDI disk that I have ever used uses an RLL (2,7 RLL was the exact definition, I believe) encoding method. I don't know if any MFM disks operate at >5 Megabits/second, but ESDI disks go as high as 24 Mb/s with 10 and 15 mb/s pretty common (on the Maxtor's for example). 15 mb/s (and the lower latency, around 16-18 ms for Maxtor) is pretty nice after you've dealt with some old 28 ms MFM disks for a while. -Carl- -- ******************************************************************************* Carl G. Heinzl - WA3UEN Internet: carl@cayman.com Cayman Systems, Inc Phone: 617/494-1999 x208 26 Landsdowne Street FAX: 617/494-9270 Cambridge, MA 02139 AppleLink: D0523
skipm@dorsai (Dorsai SysOp) (05/31/91)
phil@ux1.cso.uiuc.edu (Phil Howard KA9WGN) writes: > > How does one tell the difference? > > And how many different encoding systems, or other things, are relevant? > Is ESDI its own encoding system? > -- IDE drives are unique in that they allow you to flexibly determine what their drives, heads, and cylinders are. While the drive physically has a set number of heads and cylinders, you can set your BIOS to something else that is equal to or less than a drive of the same size. For example, a type 40 & type 17 drive look the same to an unformatted IDE drive since neither of those configurations exceed the total megabyte capacity of the drive. Note however, once you format them with a particular BIOS setting, the drive parameters are no longer interchangable since information has been written to the drive on what it supposed to "look like". IDE drives do NOT use true MFM encoding, they use a subset of it, long ago reffered to as MMFM by Zenith Corp, a technology used by them in their early laptops. Skip
bills@xstor.com (Bill Smith) (06/04/91)
In article <i7Js33w163w@dorsai> skipm@dorsai (Dorsai SysOp) writes: >phil@ux1.cso.uiuc.edu (Phil Howard KA9WGN) writes: >> >> How does one tell the difference? >> >> And how many different encoding systems, or other things, are relevant? >> Is ESDI its own encoding system? >> -- > > >IDE drives are unique in that they allow you to flexibly determine what >their drives, heads, and cylinders are. While the drive physically has >a set number of heads and cylinders, you can set your BIOS to something >else that is equal to or less than a drive of the same size. For >example, a type 40 & type 17 drive look the same to an unformatted IDE >drive since neither of those configurations exceed the total megabyte >capacity of the drive. Note however, once you format them with a >particular BIOS setting, the drive parameters are no longer interchangable >since information has been written to the drive on what it supposed to >"look like". > >IDE drives do NOT use true MFM encoding, they use a subset of it, long >ago reffered to as MMFM by Zenith Corp, a technology used by them in >their early laptops. > >Skip MFM drives can also be used with smaller head or cylinder entries. I have done this many times. -- ===================================================================== Bill Smith, UNIX Technical Support uucp: uunet!xstor!bills Storage Dimensions, Inc.