Fix for "Runtime Error 200
" bug
of Borland Pascal 7 on fast PCs
Explains the cause of this bug and sumarizes solutions
both for users and developers
(people who do have / don't have pascal source of their programs).
Also available:
Contents:
Borland Turbo Pascal 7 is a great Pascal compiler for PC's.
Unfortunately it has not been updated by Borland for many years
(for a possible alternative see
FPC).
All programs compiled with Borland Pascal 7 that use the system unit Crt
(almost all programs do that) abort with the error message
"Runtime Error 200" on all fast PCs,
for example Pentium II with 233 MHz.
Programs compiled with Borland Pascal 6 are said to not abort with a
runtime error, but their delay is completely wrong on fast PCs (and the
problem starts there at much lower speeds than the problem of
version 7).
This Web page tries to explain the problem
and summarize some existing solutions.
Borland
(aka Inprise) does not
offer a solution for this bug (shame on them!).
Instead their
Pascal Developer Support recommends an
Altavista search, which
probably is how you have found this web page.
The bug is in the initialization for the delay procedure
that is part of the initialization of the Crt unit.
The delay initialization is called in every program that
uses the Crt unit, not just on those that use the delay procedure.
The Crt unit is included in most programs that are written in Borland Pascal.
The delay initialization counts how often a tiny do-nothing loop must be
called in order to delay by 55 milliseconds (time measured by reading
the Bios Time Counter at memory address 40:6C that ticks 18.2 times a
second, i.e. each 55 milliseconds).
This number is then divided by 55 to get the number of calls for one
millisecond. The result is written to a word (16 bit) variable. The
overflow of this variable triggers the run time error (the meaning of
Runtime Error 200 is division by zero, but it is caused by an overflow
in this case).
The following list shows all solutions that I currently know.
If something is missing here, please tell me:
hartnegg @uni-freiburg.de
Index of recommended solutions
- You have only an EXE file, no Pascal source
- ask the person who does have the pascal source for a new
or recompiled version
- TpPatch
Patch program for existing executable files
(caution: only for programs that no not require correct timing)
- if you need correct timing, you may experiment with tp7p5fix
from the other solutions below, it doesn't tell if such
programs work with that or not (probably not but maybe worth a try).
- You have pascal source and the Turbo Pascal compiler
- T7TplFix
patch program for Run Time Library file (TURBO.TPL
)
- NewDelay
unit with delay replacement (good) and error trap (a bit dubious)
- RDelay
unit with delay replacement and runtime patch routine
- extract the file CRT.DIF from
T7TplFix,
apply the listed changes to CRT.ASM and then recompile the run
time library yourself.
(Only possible if you have the source of the run time library,
i.e. you have Borland Pascal, not Turbo Pascal.)
Note: If you have Turbo Pascal or Borland Pascal version 7.0,
I recommend you contact
Borland /
Inprise
to obtain version 7.01 because version 7.0 contains several bugs.
Lately there have been reports in usenet that Borland doesn't
know about a 7.01 bug fix version, it's still called 7.0,
so it may be better to ask for replacement disks for version 7.0
(will come as one cdrom containing version 7.01).
Index of other solutions
- bppatch
Solution by German computer magazine c't
- contains description, program patch, source patch
and copy of patched run time library
problem: rtl is based on version 7.0, thus reintroducing several
old errors while fixing one new one, description and patch are
very good though.
- bp7patch
patch program for all Run Time Library files
- problem: does much more changes than can be easily explained
- tp7p5fix
TSR program, catches error while program starts
- problem: no description available how and how well this program works,
probably only for programs that do not require precise timing
- tpbug new TPL files
- problem: contain much more changes than can be easily explained
Looking through the list of files above, most of you will probably come
to the conclusion that no real solution seems to be available.
Programmers using Turbo Pascal 7.01 can now solve their problem
since t7tplfix.zip is available.
Programmers using Borland Pascal 7.01
and still must search and apply the patch themselves to get a working
version of TPP.TPL (for protected mode). Users without source of their
programs can still not get a real solution if the programs rely on a
precise delay function. Such a solution will probably never exist.
Of the two files recommended by Borland, one will cause the delay procedure
to not run correct on fast computers, the other can be used only by owners
of the full Borland Pascal package because the file TPP.TPL is required
and it does a lot of suspicions changes to other units as well.
By using any of the other files, you must send your customers a program
that is patched to patch itself at runtime with even its authors saying that
this is not very nice. Or you can prevent the run time error but must
live with a delay procedure that is known to run at unpredictable
speeds. Or you must persuade your customers to install a TSR program
that you don't know precisely what it does. Or you reintroduce
all the bugs of Borland Pascal 7.0 when replacing a otherwise
correct version 7.01 with a patched version 7.0. Or you can used
a patched run time library that contains a lot of additional
changes that nobody has yet explained.
It is a shame for Borland that they seem to be unable or
unwilling to solve this bug themselves and offer download of fixed
TURBO.TPL and TPP.TPL files from their web page!
If you feel like you should say Borland what you think about their
support, please remember they have changed their name to
Inprise, so you may try
mailing to
customer-service@inprise.com (if you get a reply, please tell me).
- 26-May-1999 new patch for Runtime Library of Turbo Pascal versions 7.0 and 7.01
A new version of t7tplfix.zip is available
here.
It should be able to patch files TURBO.TPL, TPP.TPL, and CRT.TPU
of Turbo Pascal and Borland Pascal versions 7.0 and 7.01.
Please note that I still recommend updating to the bug fixed version
7.01 that could already be patched with the previous version,
but if you don't want difficult discussions with Borland,
this is an alternative to fix at least the most annoying bug.
- 29-Sept-1998 similar Bug found in Windows-95
Borland is not the only company that didn't expect computers to
become that fast and thus having bugs in their progams:
A similar error has been found in Windows-95: on computers with
an AMD K6-2 with 350 MHz or more the driver IOS.VXD causes a
division by zero because it contains a timing loop that
overflows on computers with too high speed.
For more informations about this see
www.amd.com/products/cpg/k623d/win95_update_k6.html.
This problem is solved by the patch amdk6upd.exe that can be
downloaded from Microsoft (go to their homepage, click on
search and enter the filename) or try
this webpage (link
probably works only limited time because Microsoft often
rearranges their web pages).
- 22-Aug-1998 Patch Program available
T7TplFix.zip
patch for run time library TURBO.TPL of Turbo Pascal 7.01
- 22-July-1998 new version of bp7patch.zip
does not require TPP.TPL any more, i.e. works if you
have Turbo Pascal, not Borland Pascal
Some other web pages that contain informations about this topic:
Official and of no big help:
Inofficial but much more help:
More about Borland Turbo Pascal:
Last change: 22-Aug-1998
Collection and Descriptions © 1998 by
Klaus Hartnegg
All information and programs mentioned herein are provided without warranty.
Use all on your own risk.
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(Counter started 21-July-1998)