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General Category => Technical Support - General => Topic started by: minwah on 12:19, 20 February 20

Title: Old disks - read fail
Post by: minwah on 12:19, 20 February 20
A few years ago I replaced the drive belt, and cleaned the head in my 6128. I backed up all the (non protected) disks I could to a HxC device, but some of the disks would not read (read fail). As for things like games on protected disks, again, some load perfectly, some do not. At the time I put the read fail issues down to the disks going 'bad'...they have been stored in a loft for 20+ years which I know isn't ideal.

I've recently revisited my old disks and basically have the same issue. Was my assumption about 'bad disks' correct? If the disks are to blame is there anything I can do? I have read conflicting information about cleaning, and do not know if that will help. I do not suspect a drive issue as the disks that work consistently work. I would say approx. 50% of the disk sides I have work. Often one side of a disk will read, but the other side of the same disk will not.

(I actually have another 6128 but the drive in it doesn't work. I should try fixing that to see if it reads any better...)
Title: Re: Old disks - read fail
Post by: ComSoft6128 on 14:06, 20 February 20
If you get stuck and they are important to you send them to me (with a a SAE/JIFFY BAG), I have a few working machines here and can check them out for you.

Cheers,

Peter
Title: Re: Old disks - read fail
Post by: Bryce on 16:45, 20 February 20
There's a good chance that the disks really are just bad. But I'd check the RPM (rotation speed) of the drive and retry them again. If the drive is spinning the disk too fast, then you'll get more errors. Slowing the drive down slightly may make some of the non-readable disks readable again. For commercial software this is mainly pointless as you will find most of them already dumped online, but if you have any unique disks with your own work on them, this could be worth a try.


Bryce.
Title: Re: Old disks - read fail
Post by: minwah on 18:05, 20 February 20
Quote from: ComSoft6128 on 14:06, 20 February 20
If you get stuck and they are important to you send them to me (with a a SAE/JIFFY BAG), I have a few working machines here and can check them out for you.
Many thanks for the offer, much appreciated. I will see how I get on...
Title: Re: Old disks - read fail
Post by: minwah on 18:10, 20 February 20
Quote from: Bryce on 16:45, 20 February 20
There's a good chance that the disks really are just bad. But I'd check the RPM (rotation speed) of the drive and retry them again. If the drive is spinning the disk too fast, then you'll get more errors. Slowing the drive down slightly may make some of the non-readable disks readable again. For commercial software this is mainly pointless as you will find most of them already dumped online, but if you have any unique disks with your own work on them, this could be worth a try.

Thanks for the tip. How would I go about checking the RPM? Is there a software method or would it need to be measured with some sort of test equipment?

I agree about the disks, all of the commercial ones have been dumped (bar one I managed to dump the other day), but have a few of my own that I would like to save (although nothing particularly great on them!). I'm more interested to be sure that the drive is ok, so I'll see if I can get my other drive working...
Title: Re: Old disks - read fail
Post by: Bryce on 18:24, 20 February 20
You need to get this onto a disk and running on your CPC: http://www.cpcwiki.eu/forum/applications/dsktest-v0-1b/

The RPM should be 300. Option 5 will run the RPM test, make sure you've chosen the correct drive too.

Bryce.
Title: Re: Old disks - read fail
Post by: minwah on 11:24, 21 February 20
Quote from: Bryce on 18:24, 20 February 20
You need to get this onto a disk and running on your CPC: http://www.cpcwiki.eu/forum/applications/dsktest-v0-1b/ (http://www.cpcwiki.eu/forum/applications/dsktest-v0-1b/)

The RPM should be 300. Option 5 will run the RPM test, make sure you've chosen the correct drive too.

That's great, many thanks, will give it a go.

I managed to get my other 6128 drive working last night (it was just a motor power issue, dry joint on CN3) so am going to try that one to see if it fares any better. Will also run the RPM check on that one for comparison.
Title: Re: Old disks - read fail
Post by: minwah on 11:53, 25 February 20
Quote from: minwah on 11:24, 21 February 20
I managed to get my other 6128 drive working last night (it was just a motor power issue, dry joint on CN3) so am going to try that one to see if it fares any better.
It does fare better...managed to read all of my 'blank' discs, albeit with some read errors. Haven't been through everything yet but so far have only found a handful of things which are corrupted. Still won't read several of my commercial games discs so assume they are bad. The drive test program returns this drive speed as 305 RPM which is ideal...I haven't tested the speed of the other drive yet.

Interestingly I have found that the most reliable type of disc I have seems to be Dixons blue discs - I don't have many of them but they all read without error and ones I have tried to format do format ok, with the exception of one side. Amsoft discs seem to be next in reliability, followed by Maxell...although neither of these brands will format, of the ones I've tried.
Title: Re: Old disks - read fail
Post by: GeoffB17 on 14:09, 25 February 20
Don't forget that much of what you're talking about is relative.   If your drive is mis-aligned (for whatever reason) and has been so for some time, then anything that was written on it while it was mis-aligned may well read perfectly, but another disk written on a correctly aligned drive will not.   Some of the things you describe could tie up with this.

It would be MUCH preferable to have your drive(s) compatible with the 'standard' so you can read 'normal' disks, and equally important, other machines car read your disks.

If a disk formats fine on one drive, and then reads fine on another drive - this is a better test.

Geoff
Title: Re: Old disks - read fail
Post by: minwah on 18:11, 25 February 20
Quote from: GeoffB17 on 14:09, 25 February 20
Don't forget that much of what you're talking about is relative.   If your drive is mis-aligned (for whatever reason) and has been so for some time, then anything that was written on it while it was mis-aligned may well read perfectly, but another disk written on a correctly aligned drive will not.   Some of the things you describe could tie up with this.

I hadn't really thought about that, however... In this case all of my 'blank' discs were written to by my original CPC6128 back in the early-mid 90's. I do not believe the drive was misaligned at that time (it was very well looked after, and read all commercial discs I ever used back then).

The machine I am now using to read the discs is the very same machine. It has been stored in a loft over the years but not (otherwise) mistreated. I have replaced the belt, cleaned the head (& recently fixed a dry joint) on the drive in this machine. As I say it does read all of my old 'blank' discs but with some read errors (put this down to the discs). It only runs about 1/3 of the commercial games I have...put this down to the discs as well, which seems likely given they have been in a loft for ~25 years.

On the other machine I have, it more or less has the same problems with the same discs, but with seemingly more read errors on my 'blank' discs. The same commercial games work / don't work on both machines.


Quote
It would be MUCH preferable to have your drive(s) compatible with the 'standard' so you can read 'normal' disks, and equally important, other machines car read your disks.

If a disk formats fine on one drive, and then reads fine on another drive - this is a better test.

Sounds reasonable, I haven't tried that yet. Also I haven't tried to format every disc on both machines, but ones I have tried will not format on either.

To be honest I am fairly confident the discs are just passed their best. For example I have a compiliation which has two discs, so identical brands, age etc. Disc 1 (both sides) works fine on both my CPCs, and Disc 2 side 1 always fails on both CPCs.
Title: Re: Old disks - read fail
Post by: GeoffB17 on 18:35, 25 February 20
Yes, from what you describe in detail, you may be correct.   However, I have a PCW which I got in 1985, and used it a lot back then, until I gradually migrated to PCs   The PCW was used by my mother for a while, then back with me.   I started using it again as a 'vintage' machine re CP/M etc more recently, and all my disks, of various sorts but mostly as written in the 1980s have all worked fine.   Both 3" and 5.25" (I have an external drive B: for my machine).   So I've always found floppy disks very reliable even over 30 years.   Then again, I've always taken care of them.

Oh, the disks that will not format.   If you've tried a format, and it does not work, you might try to 'wipe' the disk first with a magnet, using a rotating movement on both sides.   Then try the format again.   This might refresh the magnetic coating.   It's worked for me in the past, esp with HD PC disks.

Geoff
Title: Re: Old disks - read fail
Post by: minwah on 15:19, 27 February 20
Quote from: GeoffB17 on 18:35, 25 February 20
Yes, from what you describe in detail, you may be correct.   However, I have a PCW which I got in 1985, and used it a lot back then, until I gradually migrated to PCs   The PCW was used by my mother for a while, then back with me.   I started using it again as a 'vintage' machine re CP/M etc more recently, and all my disks, of various sorts but mostly as written in the 1980s have all worked fine.   Both 3" and 5.25" (I have an external drive B: for my machine).   So I've always found floppy disks very reliable even over 30 years.   Then again, I've always taken care of them.

Oh, the disks that will not format.   If you've tried a format, and it does not work, you might try to 'wipe' the disk first with a magnet, using a rotating movement on both sides.   Then try the format again.   This might refresh the magnetic coating.   It's worked for me in the past, esp with HD PC disks.
Thanks for the tip!
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