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editorreverse-engineeringpassword-protectionbasicgw-basic

How do I view the source code of a GW-BASIC .BAS file?

I have an old .BAS file that I'm trying to view and for which I'm running into some problems. Searching online seems to indicate that I should be able to just open it in NOTEPAD.EXE or similar, but doing so gives me gibberish, like this:

þ*©¿TÜ…7[/C̸yõ»€¹Ù<Ñ~Æ-$Ì™}³nFuJ,ÖYòÎg)ʇŒ~Š¯DËðïþSnhœJN
‰=É™2+df”c).vX»[šû'Û9¹8%ñx5m#8úV4ÊBº)Eª;Iú¹ó‹|àÆ„72@Ž§i§Ë @îÑ?
í‘ú™ÞMÖæÕjYе‘_¢y<…7i$°Ò.ÃÅR×ÒTÒç_yÄÐ
}+d&jQ *YòÎg)ʇŒ~Š¯DË?úŽ©Ž5\šm€S{ÔÍo—#ìôÔ”ÜÍѱ]ʵ¬0wêÂLª¡öm@Å„Ws雦 X
Ô¶æ¯÷¦É®jÛ ¼§
”n ŸëÆf¿´ó½4ÂäÌ3§Œ®

I know the file is sound, because I can open it in GW-BASIC. However, list does not seem to work to view the file, and trying to save the file in ASCII format from within GW-BASIC, didn't work either. Both just gave me an "Illegal function call" error:

GW-BASIC 3.22
(C) Copyright Microsoft 1983,1984,1986,1987
60300 Bytes free
Ok
LOAD"Pwrharm
Ok
LIST
Illegal function call
Ok
SAVE "Pwrharm2",A
Illegal function call
Ok
RUN
[Program runs successfully]

Then again, the run command works just fine. What am I doing wrong?

Solution

  • You're not doing anything wrong; the file was originally saved in GWBASIC with the ,P option. There is a 'hack' to unprotect it, described at https://groups.google.com/forum/#!topic/comp.os.msdos.misc/PA9sve0eKAk - basically, you create a file (call it UNPROT.BAS) containing only the characters 0xff 0x1a, then load the protected file, then load UNPROT.BAS, and you should then be able to list and save the program.