CompuServe Thread

Read/Write Again?

5 messages in this thread
#57838From: Don Curtis/SYSOPJul 19, 1989 1:42 AM
The key # is the sector number where the error occured IN THE FILESYSTEM, it is not the absolute sector number on the drive. On the R/W error does it just say that Drive so and so has a read/write error? IF so, what happens when you have it re-try? Doesn't you Disk Validator (???) give you a sector number also, or just the cylinder and head?
#58096From: ROBERT SALESASJul 20, 1989 11:23 PM
Ok, thanx I got a new DV program that told me the sector number… Is tha number I use as a key? the sector number that it returns? They are between 0 and 16 all the time.
#58128From: Don Curtis/SYSOPJul 21, 1989 1:46 AM
Robert, NO, if your "DV" program reports a sector number, along with the cylinder and head number…then you've got all you need. For the byte offeset use the following formula: (reported sector number times 600) + 300 example, DV reports sector 5 is bad. (5 x 600) + 300 = 3300 Feed that number to PREP as the byte offset. Your only remaining question is what the cylinder number reported by DV means….is it the cylinder number from the beginning of the disk, or the beginning of the partition? If from the beginning of the partition, you'll need to add the starting cylinder # from the mountlist (LowCyl) to the reported cylinder to map out the proper spot. Otherwise, if the reported cylinder number is the number from the start of the drive, you can use it as is. Also note (and others reading this thread), the above forumla ONLY works if the reported sector is 0 based (first sector is sector #0), otherwise you SUBTRACT the 300 rather than add it. Don
#58211From: ROBERT SALESASJul 22, 1989 1:08 AM
THANK YOU!!! You just saved me hours of problems!!! I wonder why C-A didn't include good programs and/or docs with the 2090A??? Could it be they are just plain STUPID!
#58214From: Don Curtis/SYSOPJul 22, 1989 2:14 AM
Robert, Because what I gave you was a kludge..one that works simply because it fakes PREP into thinking that there's an error in the middle of a sector and thus causes it to be mapped out during FORMAT. There are a few circumstances where the kludge I gave you won't work so it's certainly not something that could be documented with the software. Don