First of all, thanks to the Dennis' for the explanations.

Thus it was written in the epistle of Dennis Handly,
> Ted Ashton ([log in to unmask]) wrote:
> : but this program was working fine with XLIBTRAP . . . :-/
>
> How, wasn't there another range check?  (Ah, which you also trapped...)

Right.

> : It appears that even though PASESC.PUB.SYS still contains the line:
> :   PasErr_620    = 40632512;  PasErr_BoundsViolation    = 40632512;
> : bounds violations are not getting handed to XLIBTRAP.
>
> I don't see the connection between PASESC and XLIBTRAP?  PASESC is for
> escape codes.   It just so happens that the Pascal runtime uses the same
> numbers for some of XLIBTRAP.  But not the Trap subsystem.
>
> Ah, 620 is for CM only, for NM, since range checking is not done by a
> library call, it was replaced by Trap_Range_Error.

Right again.  Thus the problem.  A value out of subrange *used* to fall under
the XLIBTRAP domain but has now moved to the (undocumented) XCODETRAP domain.

> : The only way to catch them is a Try/Recover.  Looks like I've got some
> : recoding before me.
> : Ted
>
> You could turn off range checking for that statement.  But you'll still
> have to know that you read a bad value.

Tried that.  It works fine for the Enumerated Input problem--which I described,
but fails completely for a simple out-of-subrange check elsewhere :-(.  If
I'd've heard of XCODETRAP in time, I'd've probabaly used that (whether that
would've been good or bad I leave to others to decide).  As I didn't and I'm
under ASAP pressure, I've ripped XLIBTRAP completely out, replacing it with
Try/Recover.

Anywho.  Thanks to all.

Ted
--
Ted Ashton ([log in to unmask]), Info Sys, Southern Adventist University
          ==========================================================
Mathematics is the only instructional material that can be presented in an
entirely undogmatic way.
                                        -- Dehn, Max
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         Deep thoughts to be found at http://www.southern.edu/~ashted