[Coco] Re: Floppy Drive and OS-9

[Gene Heskett]

On Sunday 30 July 2006 01:04, Diego Barizo wrote:
>You mean that when there is no disk in the drive, I should move the
>lever to the "closed" position, just as when it's in use????
>
>Diego
>
There are two schools of thought on that. Because the springs that squeeze 
the hub rosette closed can, with the constant compression that exists when 
the lever is open, resulting eventually in poor gripping of the disk hub 
when closed, one should reduce that compression when there is no disk in 
the drive by closing then.

The other school of thought is that most of the rosettes are plastic, and 
having that pressure on them when there is no disk in the drive eventually 
leads to the fingers eventually collapsing and taking a set, which reduces 
their diameter a few thousanths in addition to lowering the squeezing 
force on the disk hub, which in turn results in erratic centering of the 
disk along with possibly a slipping drive.

In my own history I've seen failures from both effects at one time or 
another.  Particularly in 8" drives since those disks are much harder to 
turn after the disk lub has evaporated over the years.  I also had one 5" 
drive, in a tandy box no less, meaning no cooling, that appeared to have 
gotten hot enough to visibly warp the rosette, but this drive was in the 2 
drive system I built for the GVG 300 switchers EDISK lookalike, and was 
closed on both its data disk and its boot disk 24/7/365 for many years.

It got funkity after an air conditioning failure that ran the control room 
above 110F for several hours many years ago.  The AC people couldn't 
understand why we were having kittens at the time because it was like 5 
below outside, why did we need air conditioning?  Jerks couldn't think at 
all.  The control room was in the core of the building and back in those 
days consumed around 45kw of power.  I wound up replacing both of those 
drives eventually.  I also had them rig a bypass that would allow sucking 
outside air directly into the return plenum, which made quite a diff when 
it was enabled.

At the end of the day, its probably going to depend on ones personal 
superstitions as to the resting position of the lever. :)

>Gene Heskett wrote:
>> They are only required for shipping purposes, just close the levers
>> when theres no disk in them, they'll be fine.
>>
>>> Thanks again!
>>>
>>> -- Andrew L. Ayers
>>>    Glendale (Phoenix), Arizona

-- 
Cheers, Gene
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