TURBO BASIC

Le@nder

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May 7, 2001, 3:48:46 PM5/7/01

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Hi

I looking for a decompiler for Turbo Basic / 1987
I have a program that i need to decompile because
i lost the real source.

who wants to help me out of this problem.

Best regards
Leander

Dave Navarro

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May 8, 2001, 10:31:38 AM5/8/01

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In article <y_CJ6.20303$y7.1...@dbsch1.home.nl>, prive...@home.nl
says...

> I looking for a decompiler for Turbo Basic / 1987
> I have a program that i need to decompile because
> i lost the real source.
>
> who wants to help me out of this problem.

Can't be done. The compiling process is "one-way". Just as you can not
run hamburger backwards through a meat grinder to get steak, you cannot
de-compile "true compiled" executables from languages like PowerBASIC,
Turbo Basic, QuickBasic (the compiler, not the QBASIC interpreter),
C/C++, Delphi, etc.

You can "disassemble" them into assembler/machine code, but unless
you're a *REALLY GREAT* assembler programmer, the code isn't going to
help you much.

--Dave

Lance Edmonds

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May 8, 2001, 11:18:50 AM5/8/01

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Hi Leander,

I hate to break the bad news to you, but you won't find a decompiler
for TurboBasic (or PowerBASIC for that mattter) - thre has never been
one to the best of our knowledge.

This is becaise the compiled code is pure machine code and there are
no symbol tables to restore variable, sub, function or label names.
Further, calls to the runtime library and code optimization makes
decomilation almost impossible.

If you'll excuse the old adage, It is akin to converting the hamburger
back into the cow. <ouch!>

I'm afraid you'll have to face the task of rewriting the app again.
Sorry!

"Le@nder" <prive...@home.nl> wrote:

Lance
PowerBASIC Support

Le@nder

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May 8, 2001, 2:19:36 PM5/8/01

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Thanks

Le@nder

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May 8, 2001, 2:19:44 PM5/8/01

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Thanks

Le@nder

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May 8, 2001, 2:19:25 PM5/8/01

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Thanks

Le@nder

Michael Mattias

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May 8, 2001, 2:05:46 PM5/8/01

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Lance Edmonds <lancee...@SPAMLESS.xtra.co.nz> wrote in message
news:3af8099d....@enews.newsguy.com...

> Hi Leander,
>
> I hate to break the bad news to you, but you won't find a decompiler

> for TurboBasic (or PowerBASIC for that mattter) ....

> I'm afraid you'll have to face the task of rewriting the app again.

Or, learning how to "back up."

> Sorry!

You know, I am not sorry. Those who don't back up, or license custom
software without access to the source code are just asking for trouble.

(Sheesh, am I a tight-ass, or what?)

You may not need the source code when the software is delivered, but it's
MANDATORY to secure the RIGHT to obtain the source code. I used to write
contracts, and at a minimum there was always a provision to secure the
source code if the vendor went out-of-business, or could not honor a
modification request within some time frame. Sure, when you take delivery of
source code, you generally lose any warranty features; but given "no
warranty" or "no source code", I'll take "no warranty" in a New Yprk
minute.

MCM

Ken Sims

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May 8, 2001, 3:20:37 PM5/8/01

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On Tue, 8 May 2001 10:31:38 -0400, Dave Navarro
<dave.n...@basicguru.com> wrote:

>In article <y_CJ6.20303$y7.1...@dbsch1.home.nl>, prive...@home.nl
>says...
>> I looking for a decompiler for Turbo Basic / 1987
>> I have a program that i need to decompile because
>> i lost the real source.
>>

YEA His dog ate it.

>> who wants to help me out of this problem.
>
>Can't be done. The compiling process is "one-way". Just as you can not
>run hamburger backwards through a meat grinder to get steak, you cannot
>de-compile "true compiled" executables from languages like PowerBASIC,
>Turbo Basic, QuickBasic (the compiler, not the QBASIC interpreter),
>C/C++, Delphi, etc.
>
>You can "disassemble" them into assembler/machine code, but unless
>you're a *REALLY GREAT* assembler programmer, the code isn't going to
>help you much.
>
>--Dave

Ken Sims
HOME PAGE Detroit-MI. U.S.A. "http://www.megsinet.net/~mrken/mrken.html"
E-mail : mr...@megsinet.net
All in a day's work for..."Confuse-a-Cat"!
Signature data created by SIG.EXE rel 1.0 (c) 1999-2000 KASA Entertainment-Presents
On 05-08-2001 at 14:24:30 For Ken Sims

Tom Hanlin

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May 18, 2001, 4:33:55 PM5/18/01

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> I hate to break the bad news to you, but you won't find a decompiler
> for TurboBasic (or PowerBASIC for that mattter) - thre has never been
> one to the best of our knowledge.
>
> This is becaise the compiled code is pure machine code and there are
> no symbol tables to restore variable, sub, function or label names.
> Further, calls to the runtime library and code optimization makes
> decomilation almost impossible.

"Impossible" isn't quite the right word. Compilers generally do produce
quite regular and predictable output. However, the results would not be
particularly comprehensible, as you'd presumably lose all symbol names
(variable names, labels, function names, etc). It would also require a vast
amount of effort by a master programmer with an appropriate background.
Chances are, you'd rather spend your money on a nice house and rewrite the
software from scratch.

FWIW, the calls to the runtime library actually make it easier, and Turbo
BASIC didn't do the kind of code optimization that would make decompilation
difficult.

phil

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Oct 27, 2001, 3:27:19 AM10/27/01

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You can get a decompiler (such as DumpPE or DASM32) but you'll end up with
assembly. If you know assembly fairly well you can figure out what is going;
however, I suspect this will be more trouble for you than it is worth.

mov [trash], concept ; oh well !

phil :)

ps for any critics (gosh not here on a newsgroup hehe) who say that will not
assemble (x86), it will if above it resides: trash EQU eax :p