pjj@r2.uucp (Pete Jinks) (02/17/90)
I am trying to write a floppy disc tester to check the magnetic medium. i.e. write a known pattern to disc & check that it is there on reading. (and perhaps patch the FATs (& directories?) if it finds a new fault) 1) Although formatting sometimes detects faults, why doesn't it always do so ? Is it because I need to use several different test patterns (slow) ? 2) Does such a program exist already ? If not, would people like a copy if & when I get it working ? 3) To speed things up, I am trying to access a track at a time. With 2-sided, 9 sector per track discs, rwabs will not let me read 18 sectors, but will let me read 9 - is this as expected ? 4) I would also like to reposition the read/write head over the next track while I am checking the previous track - how can I do this ? Are there any other ways to speed things up ? 5) I suspect that TOS will automatically check the sector(s) written to disc for me - is this so ? how can I turn it on (or check that it is on) if it is optional ? 6) Like an idiot, as I was using C for the first time, I accessed drive '0' instead of drive 0 (i.e. 0x30 instead of 0x00) and got to my hard disc. Which partition did this access ? I think that I corrupted a sector & want to get the right replacement from backup. Which hard drives can be write protected ? Is there software available which will "write protect" my hard drive ? (I don't mean virus-proof it) 7) I have been offered a formatter that will give 11 sectors per track. Could anyone with experience of using discs with 10 or 11 sectors per track comment ? Thanks for any help that you can give me.
mwnewman@watmsg.waterloo.edu (mike newman) (02/19/90)
In article <690@m1.cs.man.ac.uk> pjj@r2.uucp (Pete Jinks) writes: >7) I have been offered a formatter that will give 11 sectors per track. Could > anyone with experience of using discs with 10 or 11 sectors per track > comment ? I've used various 10/11 sector-per-track formatters. However, I stopped using them a while back after I seemed to be getting more disk errors then other family members on the same machine. Errors included desktop claiming a non-empty disk was empty (although if booted from, auto programs would work) - usually cured by a cold boot; erasure of the boot sector - which I was able to fix by copying a boot sector from another disk of the same format; and the final straw for me - complete erasure of all fat and directory sectors on the disk. This would happen during completely normal disk usage, hence my suspicion of the extra sector formatters (although I'm not really sure). Another thing: I remember reading in an old copy of the developer docs or the abacus disk book (sorry can't remember which, I don't have it here) about the minimum space needed for the control information (required for each sector) and the acutal available space per track, and concluding that 11 sectors is impossible: it won't fit (?!?), and 10 is very tight. Does anyone know if extra-sector formatters are "playing by the rules"? Do they push the capacity beyond what it can safely hold? Is all this in my imagination? Anyone else having such problems? It would be really nice to get that extra storage. (-: It would be even nicer to get a hard disk :-) mwnewman@watmsg.waterloo.edu mike newman, co-minister of terrorism and propaganda, Cubic Earth Society :-)
csbrod@medusa.informatik.uni-erlangen.de (Claus Brod ) (02/20/90)
pjj@r2.uucp (Pete Jinks) writes: >1) Although formatting sometimes detects faults, why doesn't it always do so ? > Is it because I need to use several different test patterns (slow) ? The DESKTOP formatter checks for format errors and maps them out in the FAT. It does this by verifying the contents of the sector in memory and on disk. This test, however, is not perfect. You might use several test patterns to improve this. >2) Does such a program exist already ? > If not, would people like a copy if & when I get it working ? I have written a few programs that do parts of the job. They were published on the disk that belongs to my book SCHEIBENKLEISTER, a floppy and hard disk book. Some months ago, I started writing something like you want to write now, but never completed it. If you have a version ready, I would lllove to get one. >3) To speed things up, I am trying to access a track at a time. With 2-sided, > 9 sector per track discs, rwabs will not let me read 18 sectors, but will > let me read 9 - is this as expected ? RWABS works perfectly when being asked for 18 sectors. No problem. Are you sure you have set all the parameters correctly? >4) I would also like to reposition the read/write head over the next track > while I am checking the previous track - how can I do this ? > Are there any other ways to speed things up ? You will have to delve into direct FDC programming for doing this. Learn German and read my book 8-) 8-) >5) I suspect that TOS will automatically check the sector(s) written to disc > for me - is this so ? how can I turn it on (or check that it is on) if it > is optional ? TOS automatically verifies what you're writing on disk if the verify flag at $444 (system variables area) is set. >6) Like an idiot, as I was using C for the first time, I accessed drive '0' > instead of drive 0 (i.e. 0x30 instead of 0x00) and got to my hard disc. > Which partition did this access ? I think that I corrupted a sector & want > to get the right replacement from backup. > Which hard drives can be write protected ? > Is there software available which will "write protect" my hard drive ? > (I don't mean virus-proof it) Accessing partition 0x30 should fail and give you a RWABS error (unknown drive). At least, I think it should do so. Will reconsider that one. There are some hard drives that can be write-protected by hardware. There are also many software solutions for this problem; one of those is my hard disk driver (included in the book mentioned above) that write protects hard disk partitions. >7) I have been offered a formatter that will give 11 sectors per track. Could > anyone with experience of using discs with 10 or 11 sectors per track > comment ? > Try 11 sectors, and if your drive doesn't moan, it won't do ever. If you have a drive that spins too fast 11 sector formatting will fail because there's not enough space on the track. 10 sector formatting is perfectly safe and highly recommended. Claus Brod -------------------------- I don't know what I mean and I hate standard disclaimers.
csbrod@medusa.informatik.uni-erlangen.de (Claus Brod ) (02/20/90)
mwnewman@watmsg.waterloo.edu (mike newman) writes: >I've used various 10/11 sector-per-track formatters. However, I stopped >using them a while back after I seemed to be getting more disk errors >then other family members on the same machine. Errors included desktop >claiming a non-empty disk was empty (although if booted from, auto programs >would work) - usually cured by a cold boot; erasure of the boot sector - >which I was able to fix by copying a boot sector from another disk of the >same format; and the final straw for me - complete erasure of all fat and >directory sectors on the disk. I've written the first German 11 sector formatter called HYPERFORMAT and have more than two years of experience with this program and with the whole problem. The problems you're describing are very typical for boot sector viruses! 10 sector disks are perfectly safe. 11 sector disks might introduce some difficulties if you own a drive that spins too fast. This can be cured by adjusting the rotation speed internally. >Another thing: I remember reading in an old copy of the developer docs or >the abacus disk book (sorry can't remember which, I don't have it here) >about the minimum space needed for the control information (required for >each sector) and the acutal available space per track, and concluding that >11 sectors is impossible: it won't fit (?!?), and 10 is very tight. The Abacus disk book tells you a lot of stories, and we had a lot of fun with it laughing all night... 10 sectors aren't tight. 11 sectors are, but it works if you have a drive that spins at the correct speed. BTW: We have expanded disk capacity up to 14 sectors per track (needs a little hardware hack), and it works fairly safe. We even have connected 1.44 MB HD disk drives to standard STs (again, with a tiny hardware hack), and now we're pushing those disks to 21 sectors per track. Ain't that nice? Claus Brod