🚀 go-pugleaf

In article <sankey.728153663@unixg.ubc.ca> sankey@unixg.ubc.ca (Todd Sankey) writes:
>
>  Is there any reliable way to detect if the floppy disk has been
>changed short of actually reading it?
>
>-- 
>		Todd Sankey
>		sankey@unixg.ubc.ca
>

Many of the new disk drives support a change line status indicator.
I am not sure offhand if there is a way to read this (other than
going directly to the floppy disk controller) so you will have
to research this yourself... but other drives such as the
360K drives do not support this feature.  What MS-DOS does is
to assume that if a disk drive was last accessed more than a
second ago, then they assume that the diskette has been changed
which is a pretty good assumption.  They picked a second because
apparently after several tests they found that the minimum average
time that a person takes to open a drive and remove the disk was
about 1 second.

Check the extended INT 13H calls that the AT's introduced to see
if you can read the disk change status indicator... and also to see
if a drive supports that feature.  I believe that there were 
function calls for both.

jC
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