[comp.lang.pascal] I found a BUG in Turbo Pascal 5.5!!!!!!!!!!!!!!!!!!!!!

leif@ambush.dk (Leif Andrew Rump) (08/03/89)

Try this out on EGA/VGA/... and then on CGA/... (I haven't tried all
possibilities, but the _TWO_ result is the same every time on those
two monitors, even with or without ansi.sys. i also haven't tried
earlier versions of Turbo Pascal but it's probably the same).

I'm trying to make a window with only one line. As with any other
window it scrools if you put more in to it than there is space for
_BUT_ on a CGA/... monitor _ALL_ the lines under the window scrools
up!!!!! (see the example on the bottom of this letter).

program Turbo_Pascal_window_BUG;

uses
  crt;

begin (* Turbo_Pascal_window_BUG *)
  clrscr;
  gotoxy(1, 10);
  write('abcdefghijklmnopqrstuvwxyz{|}ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]');
  gotoxy(1, 20);
  write('abcdefghijklmnopqrstuvwxyz{|}ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]');
  gotoxy(1, 25);
  write('abcdefghijklmnopqrstuvwxyz{|}ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]');
  window(10, 15, 20, 15);
  write('abcdefghijklmnopqrstuvwxyz{|}ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]');
end. (* Turbo_Pascal_window_BUG *)

How it should be and is on EGA/VGA/... (more or less!):
----------------------------------------------------------
abcdefghijklmnopqrstuvwxyz{|}ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]

             STUVWXYZ[\]

abcdefghijklmnopqrstuvwxyz{|}ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]



abcdefghijklmnopqrstuvwxyz{|}ABCDEFGHIJKLMNOPQTSTUVWXYZ[\]
----------------------------------------------------------
How it is on CGA/... (also more or less!):
----------------------------------------------------------
abcdefghijklmnopqrstuvwxyz{|}ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]

             STUVWXYZ[\]
             nopqrstuvwxyz{|}ABCDEFGHIJKLM
abcdefghijklm                             NOPQRSTUVWXYZ[\]
             nopqrstuvwxyz{|}ABCDEFGHIJKLM
abcdefghijklm                             NOPQRSTUVWXYZ[\]
----------------------------------------------------------

  Leif Andrew Rump, AmbraSoft A/S, Roejelskaer 15, DK-2840 Holte, Denmark
 UUCP: leif@ambra.dk, phone: +45 42424 111, touch phone: +45 42422 817+313

   > > > Why are tall Irish girls with red hair so wonderful ? ? ? < < <

AWALTER@cosmo.UUCP (Andreas Walter) (08/08/89)

Dear Leif,
I've tried Your Turbo_Pascal_window_BUG.
But I didn't notice any bug.

And this is, what my screen looks like:
----------------------------------------------------------

abcdefghijklmnopqrstuvwxyz{|}ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]

             [\]

abcdefghijklmnopqrstuvwxyz{|}ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]



abcdefghijklmnopqrstuvwxyz{|}ABCDEFGHIJKLMNOPQTSTUVWXYZ[\]
----------------------------------------------------------
And there's no difference between EGA/VGA and CGA-screen.
Used configuration: 386-Clone, Orchid-Prodesiger, TP 5.5.
Note, that my CGA is the CGA-emulation of the VGA-Card.
Please notice also that the contents in my window is different
to yours.

  Andreas Walter
  Josef-Hoeren-Str. 189
  D-4300 Essen 12
  West-Germany

leonard@bucket.UUCP (Leonard Erickson) (08/10/89)

<description of problem that only shows up when using a single line
 window on a CGA  omitted>

I forwarded the message describing the problem to the Borland Forum
on Compuserve. Their response was that the "bug" is due to using CGA
on a machine with an outdated BIOS. This is a known bug in windowing
on a CGA. But the problem is in the BIOS, not in TP.
-- 
Leonard Erickson		...!tektronix!reed!percival!bucket!leonard
CIS: [70465,203]
"I'm all in favor of keeping dangerous weapons out of the hands of fools.
Let's start with typewriters." -- Solomon Short