ashing@milton.u.washington.edu (Al Shing) (08/07/90)
I used Disk Technician Pro to do a destructive low-level format on my Mitsubishi MR-535 hard disk this weekend, and to my surprise, FDISK came up and said "Error reading fixed disk" and quit. The setup defined the disk as a type 17, and this defines it as having 986 cylinders, 5 heads, and 26 sectors. A LLF with DTP a couple of months ago worked fine, so I don't think there are any compatibility problems. Eventually, I tried a program that came with my system, called HDFORM. This program marked cylinders 977-986 as bad, which is fine, because I've never had more than 977 cylinders anyway, but it also marked cylinders 0-8 as bad, which was surprising, because I've never had any problems with that area before. After HDFORM, FDISK started working, but it now starts at cylinder 9, instead of cylinder 0. This resulted in a loss of some 600,000 bytes on my hard disk. Not wanting to accept the loss of that many bytes for no reason at all, can someone tell me if there is something wrong with my LLF procedure, and if it is possible to recover cylinders 0-8 on my HD? The machine is a Leading Edge D3, 386-16 MHz system. Al Shing (ashing@cac.washington.edu)
ashing@milton.u.washington.edu (Al Shing) (08/08/90)
In article <5943@milton.u.washington.edu> ashing@milton.u.washington.edu (Al Shing) writes: >I used Disk Technician Pro to do a destructive low-level format on my >Mitsubishi MR-535 hard disk this weekend, and to my surprise, FDISK came >up and said "Error reading fixed disk" and quit. The setup defined the >disk as a type 17, and this defines it as having 986 cylinders, 5 heads, >and 26 sectors. A LLF with DTP a couple of months ago worked fine, so I >don't think there are any compatibility problems. > >Eventually, I tried a program that came with my system, called HDFORM. >This program marked cylinders 977-986 as bad, which is fine, because I've >never had more than 977 cylinders anyway, but it also marked cylinders 0-8 >as bad, which was surprising, because I've never had any problems with >that area before. > >After HDFORM, FDISK started working, but it now starts at cylinder 9, >instead of cylinder 0. This resulted in a loss of some 600,000 bytes on >my hard disk. > >Not wanting to accept the loss of that many bytes for no reason at all, >can someone tell me if there is something wrong with my LLF procedure, and >if it is possible to recover cylinders 0-8 on my HD? The machine is a >Leading Edge D3, 386-16 MHz system. > >Al Shing (ashing@cac.washington.edu) > Amazingly, I got no replies on this article. However, I was able to get the information I needed to correct my problem from the Western Digital BBS. The following is a summary of how to low level format a Mitsubishi MR535 RLL 65 MB hard disk. 1. Use DOS Debug command, and enter g=cc00:5 to invoke the Western Digital controller's LLF program. 2. Set the hard disk type to type 1 (user specified parameters). 3. Set the following parameters: 977 cyls, 5 heads, write precomp 300, 26 sectors. 4. Select the Low Level Format option on the menu, and reply "Y" twice. 5. Disk will be low level formatted and ready for FDISK. This procedure corrected my problems from using third party LLF routines on my RLL drive. I am rather surprised that Disk Technician Pro would leave my HD completely unusable, without issuing an error message of any kind. I also wish that PC manufacturers would include the documentation on the hard disk and controllers so that the user doesn't have to spend a day or two having to research his equipment. I suspect that most users are not even aware of the Western Digital BBS, which is the only place I have found that had the correct information on their controllers and compatible hard disks. (I found out about it on Compuserve, but the number given was incorrect. The correct number is in Boardwatch Magazine, and is (714) 756-8176.) Including this documentation would go a long way towards demystifying the controller and hard disk, and clear up the issue of how to low level format one's hard disk. -- Al Shing (ashing@cac.washington.edu)