Amiga 600 df0: problem
 

Hello,

i have resumed my 600 again and i have discovered that the floppy disk drive has serious problem: in fact it doesn't read well the lower side of the disk, from track 0 to track 30, and it writes them in an even worse way.

I have tried to clean the heads with the appropriate disk together with some alcool but so far nothing has changed.

When reading ( and writing, i have tried with xcopy with verify ) upper side and other tracks of the lower side it just works fine.

What it could be?

Also i have tried toggling every fix on the lower side on the amiga in order to see the floppy drive better but the case doesn't open, and i have already broken a pair of fixes on the rear part :( . Is there some particular way to follow?

I have to say also that i have a spare chinon drive from an a500 ( i believe ) that could ( never tried it ) work fine, but i also don't know if i can use it in the 600.

Thank you in advance.

Your top head is probably out of alignment.. Good luck getting that straight again.. :-(

The A500 drive will work, but you might not be able to fit the case back on the computer neatly.

It won't fit, definitely. You will have to put the diskdrive outside of the Amiga's case, like I had it for many years (in my case, with an A2000 drive, not an A500 one)

My A600 case has the same "problem". Remove all the screws etc and it still refuses to open. Took me ages, but tracked it down to press-fit clip thingies. Basically, you have to push the back of the case inwards whilst pulling the rear of the top shell away from the base. It will open, but you do need to use a little force.

It does sound like your drive heads are out of alignment. You can fix it but it's hardly worth the hassle. Without the right equipment it could take 30 seconds (very lucky) or thirty days by trial and error (very unlucky).

One way to find out is to format a new disk and then see if it's okay to use. See, if the heads are out of alignment, the freshly formatted disk will also be formatted out of alignment, but will be "in alignment" with the drive that created it - it's just that the freshly formatted floppy won't work very well on other "properly aligned" drives.

Hope it helps dude, but it looks lke you need a new internal drive (like I do!).

Thought of this: If the drive is still playing up with a newly formatted floppy, it could well be a bit of foreign matter has got into the drive and is stopping the heads from touching the disk surface - maybe a hair or something? If it's okay on the other tracks on the same surface, it shouldn't be screwing up on other tracks - unless the stepper motor is losing traction. Maybe you have a rubber drive belt needs replaing?

Thank you, i'll try again.

Anyway the case is badly assembled ( made in Philippines, 1994 iirc ).

I have already tried to format a new disk ( HD with tab closed ) but it's not fully readable.

Today i have tried again with old floppies and they work ( they are at least fully readable, i haven't tried to write to them )!

Seems that it has problem only with new hd floppies, just bought.

If i'll be able to open it i'll check that.

Thank you again.

HD disks - right there is your main problem. It takes a different level of magnetic flux density to record on a HD disk. In plain English, it's like you're trying to record something on a metal/CrO2 cassette tape when your tape deck is switched to "normal" or Ferric. It just won't record properly. My A600 drive can't read HD floppies either, but my A500 (and all my external drives) can.

If you take a close look at the disk surface of a normal (usually blue) DD disk, you'll see a dark brown surface - fair enough, but if you examine a HD disk, not only should you be able to see through it if you hold it up to a light source, it's also much darker in colour - due I think to the Cobalt content in the oxide layer.

You're lucky it reads one surface to be honest, my A600 drive takes ages thrashing about before moaning about not being able to write the disk.

HD disks written in a DD drive can tend to be unreliable - the magnetic recording on them fades long before it should. It doesn't always happen - I've got HD disks written here on a +3 Spectrum, still readable!

So, I would say, either get a new floppy drive or just use good old fashioned DD media. Hard to get now maybe, but they are what your disk drive was designed to use, and Ebay has lots of second hand ones if you're prepared to pay stupidly high delivery charges (floppies are heavier than you think).

Ebay also has lots of first hand ones..

Lots of people have keyboards and sowing machines (!) that don't write to HDs, so bulks if duplicator grade media is available every now and then.

Also you can try:
http://www.oldsoftware.com/floppy_di...l#anchor270200
http://www.smrsoftware.com/disks.htm (!)
http://www.google.com/ ;-)

Thank you for your explanation.

In fact i have a pair of 500 too and they both have no troubles with hd floppies.

So my 600 ( like your ) has troubleswith HD floppies, but now that i know i'm formatting old dd floppies in order to use them with it, so i think i'll be able to solve the problem without too many troubles and without the need to buy new dd floppies.

A note: some time ago ( a pair of months ) in an eletronic shop i saw DD floppies ( something like 1 € for 3 floppies w/out brand ), and i wondered: why? Now i have understood.

@ Jope

YEs, you can get them first hand, but the price is very high compared to HD types, especially when you add the cost of shipping. I used to know people who worked at a duplicator factory and was able to buy the surplus floppy disks that came back from magazines. A bit of hot air from a hair dryer and the old labels fell off, ready for me to format and use - just the thing for my (then) PD library. Shame all the magazines that used to have cover disks are all using CDs now

Indeed they are more expensive than HD disks, but such is life when you want something that can't be bought from store shelves any more.