22 May
2003
22 May
'03
8:16 a.m.
3.5":
Find one of each that are known, and labeled by the
manufacturer. Sometimes the labeling will refer to the UNFORMATTED
capacity and say 1M v 2M.
Find the write protect hole. Notice that on the HD diskette, there is
another similar hole in one of the other corners.
That, surely is a reliable method for name-brand disks.
3":
I don't think that there are any density differences, but single and
double sided diskettes are different. I don't remember the difference -
holes?
This is the confusing one IMHO. All 3" disks are double sided, but some
drives are single-head and use the disks as 'flippies'.
However, Amstrad, who were the major user (at least in the UK) of 3"
disks fitted 40 cylinder single-head or 80 cylinder double head drives to
their machines. With the result that 80 cylinder-capable disks were often
called 'double sided' and 40-cylinder ones 'single sided'.
But 40 cylinder double-head drives exist (I have one on my CoCo), and
obviously from the above they are reliable using so-called 'single-sided'
disks.
AFAIK the pattern of holes and notches is the same in all disks.
-tony