(Excerpts from a message dated 11-25-99, Leonard Erickson to Lee Aroner;
oroginal topic: Install)L:

Hi Leonard--

 ML> Nonsense.  Programmers of old DOS programs used FCBs long after
 ML> DOS 1.x came out, even though the documentation told them not to (who
 ML> reads the docs?).  What to set FCBS= depends on which DOS programs you
 ML> are running, not what version of DOS they were written under (something
 ML> you have no way of knowing unless you wrote them ).

 LE> Actually, I seem to recall hearing that MS-DOS has dropped support
   >for FCBS as of version 6 or 7. I know they've been *warning*
   >programmers since version 5 (or earlier) that those functions where
   >not to be used, because they'd be dropped at some future time.

 LA> This is the usual case of MS's "Do as I say, not as I do", since 
 LA> Command.Com continues to use FCBs for fast directlry deletions, 
 LA> just as I do.

LE>Try it under MS-DOS v6.x. Then try it in a Win 95 or 98 DOS "window"
  >(or with the system booted to the MS-DOS 7 that Win 9x runs on top
  >of).

    This argument gets sillier and sillier.  MS may have "warned"
programmers not to use FCBs.  MS may even have stopped supporting the
use of FCBs in its newest operating-system software.  (I wouldn't know,
as I don't own any MS software written after 1990.)  But I do know that
there is no way that MS is going to retrofit all existing DOS software,
written either before or after that warning was last issued, where the
programmer happened to use FCBs.

    This thread started on the matter of how much memory space should be
"wasted" in support for FCBs in a VDM.  Even though the likelihood of
ever attempting to run a legacy program requiring 16 FCBs is very small,
essentially nothing is lost if one keeps the full "default" FCB support:
one is "wasting" (at most) about half a kilobyte by taking this easy way
out :-).  This amount of memory space is in the noise; each VDM session
has available to it much more usable RAM than is required by any program
that would run in "real" DOS.

    IIRC, there was a row in this echo about the time of Warp 4 GA over
an error in the VDM support of FCBs.  I don't know which early FixPak
corrected this "bug" but I do know that it was corrected by the time
FixPak 5 was released. In any case, that episode made it obvious that at
least some OS/2 users are running legacy DOS programs that made use of
FCBs.

    Why, then, should a rational OS/2 user recommend risking the
possible inability to run a legacy DOS program?  MS has a history of
abandoning users of legacy software (perhaps to force them into buying
the newest bloated version ).  But there is no real reason for an
OS/2 user to jump ship by adopting MS practices :-).

    Regards,

        --Murray

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 * MR/2 2.25 #120 * Nothing is so uncommon as common sense

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