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- ************
- Sub: Blitz! and Deblitz!
- Questions (and hopefully answers) on protecting Blitzed programs from Deblitz
- ------------
- Category 4, Topic 3
- FINNER [Tom Sawyer]
-
- I have seen a few programs out that Deblitz won't decomplie. Does anyone know
- what techniques these programs use that protect them from Deblitz? When I
- write
- a program, usually Blitz is my only protection from people getting a listing,
- but Deblitz always gets me.
- ------------
- CHARRINGTON [Courtney]
-
- To keep a program from deblitzing, try this: Use one of the old simple tricks
- that people used to use to keep people from LISTING a basic program...like a
- shifted "L" in the REM statement. The de-blitzer will hit this and generally
- bomb out.
- ------------
- FINNER [Tom Sawyer]
-
- Courtney: That doesn't work. Blitz doesn't compile REM statements, so that
- isn't included in the final output. Any other ideas?
- ------------
- TIGLON.G [Gayle][SysOp]
-
- Tom, (pardon the question ...but) are you using a 'cracked' version of Blitz!?
- ------------
- FINNER [Tom Sawyer]
-
- Tiglon: No, I am using a purchased copy of Blitz. I also (should I mention
- this?) have a cracked copy, but I figure as long as I paid for it, I might as
- well use the legit copy. What does this have to do with De-Blitzing?
- ------------
- TIGLON.G [Gayle][SysOp]
-
- Tom, a few people I know who compiled the programs using a 'non-legit' copy of
- Blitz found the ending code undeblitzable. I doubt that is the problem in most
- cases, but was just wondering!! What type of programs are those that will not
- deBlitz!?
- ------------
- GRAFIX.M [Mike Hooper]
-
- There are also a couple of BLITZ clones. One of which I have seen that came
- from Germany. Altho these clones have the same general appearance as BLITZ, it
- really is different code. None of these will deblitz. Austrocompiler is the
- only one I have really taken a close look at. And, while it is a tad faster
- than BLITZ and can produce it's p-code a little tighter, it does have trouble
- with a few routines. RS-232 in particular. You might want to try one of the
- other compilers available. BASIC-64 does some nice work (altho the code ends
- up larger than BLITZ) and has a couple of super features like defaulting to
- integers in place of floating point variables (if you select it.) It does make
- for more compact code and they claim it WILL run faster than floating point
- routines.
- ------------
- FINNER [Tom Sawyer]
-
- One program I recall in particular was 6485 BBS (lousy program, byt the way).
- I tried Deblitzing this with two different deblitzers. Both of them got about
- 10 lines into the program and stopped as if that was the end. The line they
- both stopped at read:
- PRINT"This program will not Deblitz!"
- What I want to know is how did he do that? I tried calling the author's BBS,
- but it is for registered sysops only (who registers for that?!?!?), and
- promptly disconnected me at the expense of a long distance call. I have never
- seen any of these Blitz look-alikes though. Also, I do have BASIC64 and hate
- it! BASIC 128 is ok, but I have had nothing but problems with BASIC64. It
- seens to scramble a lot of the disk accessing routines.
- I know there must be a way to disable Deblitz, since the program I mentioned,
- and a couple others I don't remember, have intentionally foiled it's attempts.
- I would just like to know how.
- ------------
- DEB [*deb!*]
-
- When Chris Kaiser wrote XMOBUF, we found out that the source code was so long
- it would NOT Deblitz properly.
- ------------
- CKAISER [Chris]
-
- Apparently the deblitzer thingies get lost if there are too many variables, or
- if the subroutines are nested deeply enough. They seemed to work fine on short
- files, but the compiled version of XMOBUF I remember trying it on went almost a
- 100 blocks. The code the deblitzer made looked *sorta* like the original, but
- stuff like C5oyON X GOTO 210,220,230,240,250,260,270,280,290 seemed to blow it
- away.
- ------------
- FINNER [Tom Sawyer]
-
- I have deblitzed a few programs (other BBS files) which came out VERY long
- (200+ blocks). Although these cannot be edited on the 64's limited memory
- capacity, they are easily done in 128 mode, and usually recompile to about the
- same size. I usually try to deblitz everything I find, just out of curiousity,
- and have been successful every time except where the program was deliberately
- written to disable blitz. I hve 3 different deblitzers, so if 1 doesn't work,
- 1 of the others most likely will. But on the program I mentiond, and 1 or 2
- others I have forgotten, none of my programs would work, and always stopped at
- a place that made it obvious that the programmer had done it deliberately.
- ------------
- CKAISER [Chris]
-
- Hmmmm! Very interesting! Care to try it on XMOBUF and see if you can bust it
- out right? I made *no* effort to defeat BLITZ or DEBLITZ in it at all. It
- would be interesting to see if it does come apart correctly with 1 of those.
- ------------
- SURVIVOR [S. Gutknecht]
-
- I used to ALWAYS put "DEBLITZ! killers" in BBS programs... and the ones I
- found that worked, not sure if the "new deblitzers" will do them, Put a line
- like this:
- 10 print"deblitz killer":
- then after the ":" type a quote (") & enter a WHOLE bunch of control characters
- in reverse and all sorts... these will be illegal tokens, and the sort...one
- thing... NEVER let your program jump to this line:
-
- 10 goto100 20 print"deblitz killer:^z^t^y^w^e^l^e^w^a^b^n^h^l^r^f^47575753jgkj
- 100 start program
-
- And another way to do kill them (this 1 works good) is to load the BLITZED!
- program into memory and then SAVE it with a ML monitor with the 1-2 pges of ML
- plus the program... then the DEBLITZER gets all that "ML" it will just throw
- trash out....
- And a form of "BLITZ!" protection is to have a ML program check to see if the
- quote "BLITZ" is in memory at the start of basic (List a BLITZED program, & you
- will see "BLITZ").... and then make a call to that in your program... if the
- program is DEBLITZED the "BLITZ" string will not be there... there are MANY
- other ways to go about this... hope I helped.
- ------------
- FINNER [Tom Sawyer]
-
- Thanx Stephen. Your "BLITZ Killer" line sounds like what I saw. Maybe that's
- what I need to do. Worth a try anyway. As to your ML program, checking for
- the string "BLITZ!", that wouldn't work for me, cuzz I always change that to
- the name of the program, so it shows the program name rather than "BLITZ", but
- but maybe I could check for that.
- ------------
- FINNER [Tom Sawyer]
-
- The control character idea worked perfectly! I tried decompiling with 3
- different deblitzers, one of which just released a few weeks ago, and nothing
- made it past that line.