Unprotecting Chuck Yeager's Advanced Flight Simulator v1.0   by Independent (IND)

Unprotecting Chuck Yeager's Advanced Flight Simulator v1.0 by Ralph and The Computer Pike (22Jun87) Written by The Computer Pike Materials 1) The ORIGINAL program diskette. 2) A blank FORMATTED diskette. 3) The program DEBUG.COM (found in most MS-DOS packages). Overview The copy protection for Chuck Yeager's Advanced Flight Simulator (by Electronic Arts) was very simple, so save the $10 for the unprotected version offered by Electronic Arts. Tracing was done on the file AFS.EXE using Micro- soft's Symbolic Debug Utility - SYMDEB.COM (version 3.00). Concentrating on any disk I/O, it was found that a portion of the program had four identical groups of two CALLs bunched together. The first CALL routine was CALL 0B31, which resets the disk, reads the boot record and track 15 (side 0). By the way, track 15 (side 0) is one of those "hard to copy" tracks. The second CALL routine was CALL 0B74, which checks the status of the flags set by the last disk I/O, being CALL 0B31. Replacing these CALLs with NOPs (three NOPs per CALL), we found that the program ran with no problems whatsoever! It was that easy! As a matter of fact, we joked about the fact of merely using NOPs to unprotect the program before running it... It couldn't be that easy! Sure enough... Procedure In copying the program diskette, we decided use COPY *.*. Reasons being that it allows the COPIED diskette to rid the bad track 15 (side 0). It was found that using DISKCOPY returned errors and COPYIIPC left track 15 (side 0) in its "bad" state. So, let's do it this way... If all goes well, you'll only have to do it once! Perform the following: 1) Assuming that the PC has been booted-up and the DOS prompt is B>, insert the ORIGINAL program diskette into drive A: and the blank FORMATTED diskette into drive B:. 2) Type the following after each B> prompt: md afs copy/v a:*.* copy/v a:\afs\*.* b:\afs 3) Now, remove the ORIGINAL program diskette from drive A: and put it away... You won't be needing it anymore! 4) Insert the diskette containing the DEBUG.COM file into drive A:. 5) You'll have to rename the AFS.EXE file. Type the following at the B> prompt: rename \afs\afs.exe afs.xxx♀ 6) Now, enter debug by typing the following at the B> prompt: a:debug \afs\afs.xxx 7) At each hyphen "-" prompt, type the following: e de0 90 90 90 90 90 90 e de8 90 90 90 90 90 90 e df1 90 90 90 90 90 90 e df9 90 90 90 90 90 90 w q 8) You'll have to rename AFS.XXX back to its original name. Type the following: rename \afs\afs.xxx afs.exe 9) There! You now have an unprotected copy of Chuck Yeager's Advanced Flight Simulator by Electronic Arts... Conclusion Being an avid user of PC-based flight simulators, I'll have to say that Chuck Yeager's Advanced Flight Simulator ranks among the BEST! It's a shame that many of you frowned upon the copy protection... We hope that this document has aided in removing such a nuisance, and that it will confidently allow you to use the software freely. Have fun and good luck!!! Addendum - For single-drive users... And maybe others... First of all, I'd like to apologize to all you single-drive users. I don't think you all could have done the above verbatim. So, I went ahead and COPYIIPC'd (version 3.09) the ORIGINAL program diskette in drive A:. Ignoring the three errors that track 15 created, I went ahead and used the copy and performed the unprotection. I ran the copy with no problem. Then, I DISKCOPY'd (PC-DOS 3.2) the diskette in drive A:. Again, I ignored the errors. The DISKCOPY'd diskette also ran with no problem. Unless you have a program that corrects or formats by tracks and sides, you'll have to live with the errors popping up during copying with no effect to the actual running of the program. Such a program that allows formatting by track and side is called ULTRAFMT.COM. It is a public domain program and usually comes as a package with other ULTRA programs. The programs can be found on most BBSes under the ARC'd filename ULTRA.ARC. Again, good luck and... sorry!!! ♀