[comp.os.msdos.programmer] Why load "SHARE"

iverson@bang.uucp (Tim Iverson) (02/24/91)

In article <OTTO.91Feb14125220@tukki.jyu.fi> otto@tukki.jyu.fi (Otto J. Makela) writes:
>In article <1991Feb13.130613.13467@csc.canberra.edu.au> act@softserver.canberra.edu.au (Andrew Turner) writes:
>> An IBM Dos programmer is alleged to have said that even today Dos itself
>> still uses some of the old FCB's for some unspecified internal disk
>> functions!
>> God help us, Microsoft sure didn't.

Sure they did.  Check out comp.com.

>Well, I know that DEL, the COMMAND.COM builtin uses FCB wildcards to get the
>job done quickly.  Does anyone with a large hard disk care to try this ?
>
> Otto J. Makela <otto@jyu.fi>

Works fine.  The delete function doesn't exercise the bug, only read and
write do.  If you'd like to find out if a program uses FCBs, just set the
device open/close bit in the DOS "kernel"; as well as causing open/close
calls to go to the driver, it also has the side effect of disabling FCBs.
When a program uses FCBs, you'll see an 'abort, retry' message (sorry,
DOS can't ignore this one!).

If you don't like hacking your "OS", you could use a recent copy of the
SpeedStor device driver with the /nofcb option.  This has roughly the
same effect.

- Tim Iverson
  iverson@xstor.com -/- uunet!xstor!iverson