Quirky External Floppy Drives

[diablothe2nd]

I have two external drives, both have very little trouble at all with reading, although are slightly less reliable than my DF0 which only seems to fail me on the worst of disks, even ones that squeal like a pig still get read

anyway neither of them seem to be all that good at writing. in X-copy i'll format with verify a disk, and both DF1 and DF2 chuck out errors on the same sectors on a disk, but in DF0 the very same disk will format with little trouble (flashes red number in same sectors then goes green) and will never complain again on a reformat. verifying the same disk formatted in DF0 in either DF1 or DF2 then shows green across the board.

does this mean the drives aren't getting enough power to write? or is it mere coincidence that both drives writing heads need a clean?

i've got a floppy head cleaner disk with fuzzy stuff where the drive heads go. put that in and "formatted" without verify so the writing heads get a rubbing, and put it in and pulled it out numerous times to get the read heads to rub on the fuzzy stuff. No difference.

[Stedy]

Did you try some Isopropyl Alcohol on the drive cleaner?
If you don't have any, your best vodka or gin will do as an alternative

Can you try just one external drive at a time, see if the problem persists, this will help rule out power issues.

Ian

[roy bates]

have you had a look inside the drive to make sure theres nothing wrong with it mechanicly?

check the disk pushes the switches all the way down etc(this means the disk has to go in all the way,it only makes sense when you see how it works),some external drives use a third switch on the right hand side and those dont like hd floppys being inserted.
or even drive head allignment problem maybe.
i dont think it will be a power problem as your internal one works with the external one plugged in at the same time(i have to assume this as i cant see it)

also check what type of drive it is,some use a drive belt that may be worn and effecting timing.(most of the ones ive seen are direct drive)

[diablothe2nd]

Did you try some Isopropyl Alcohol on the drive cleaner?
If you don't have any, your best vodka or gin will do as an alternative

not yet. and FYI as a brewing/distilling semi-professional I wouldn't recommend Gin, as the oils from the botanicals in the still head pass over to the distillate (giving it the flavour). probably wouldn't do much good on electrical components... I'll give vodka a try though

Can you try just one external drive at a time, see if the problem persists, this will help rule out power issues.

shall try that too

have you had a look inside the drive to make sure theres nothing wrong with it mechanicly?

not yet, as the symptoms are equal between two different brands of external drive

check the disk pushes the switches all the way down etc(this means the disk has to go in all the way,it only makes sense when you see how it works),some external drives use a third switch on the right hand side and those dont like hd floppys being inserted.

drives read fine, tests done with both DD and HD floppies. EDIT - when i say fine, i mean they both read the same sector errors even if DF0 reads it fine

also check what type of drive it is,some use a drive belt that may be worn and effecting timing.(most of the ones ive seen are direct drive)

as above, drives are different but have same symptoms, would be one hell of a co-inky-dink if they both suffered the same problem.

EDIT DF1 is a Cumana Drive, DF2 is a PowerComputing drive

[demolition]

Maybe the heads have slightly different alignments? It could just be by chance that your two external drives have the same alignment.

[diablothe2nd]

i've since tested both drives on their own, and they both work fine?!

seems to be a power problem then.

[prowler]

Originally Posted by diablothe2nd

i've since tested both drives on their own, and they both work fine?!
seems to be a power problem then.

Yes, that was always the most likely explanation (as first spotted by Stedy above). Some external drives are surprisingly power-hungry - especially the Cumana (~900mA, just while reading a disk, IIRC).

Originally Posted by diablothe2nd

DF1 is a Cumana Drive, DF2 is a PowerComputing drive

Edit: Here's the result of my current measurements on a Cumana external Amiga floppy drive:
http://eab.abime.net/support-hardwar...tml#post577462

[diablothe2nd]

so, better to swap the cumana drive to last in the chain?

how the heck did people manage with THREE external drives then?

wonder if it'll be any better now that power is coming via the mediator and much more powerful PSU than the one i bought from AmigaKit with the square amiga plug.

[prowler]

Originally Posted by diablothe2nd

so, better to swap the cumana drive to last in the chain?

That won't make any difference when they're both in use.

Originally Posted by diablothe2nd

how the heck did people manage with THREE external drives then?

Commodore actually recommend no more than two, IIRC.

Originally Posted by diablothe2nd

wonder if it'll be any better now that power is coming via the mediator and much more powerful PSU than the one i bought from AmigaKit with the square amiga plug.

It might do. It all depends on how exactly the current is distributed along the various paths to the external drive socket.