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Re: Free Apple II GS With The Works to Help with LemminGS Source Code
On Tuesday, 8 January 2013 23:27:19 UTC-6, BLuRry wrote:
> On Tuesday, January 8, 2013 11:19:48 PM UTC-6, applek...@gmail.com wrote:
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> > On Tuesday, 8 January 2013 22:56:24 UTC-6, BLuRry wrote:
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> > > On Tuesday, January 8, 2013 10:34:18 PM UTC-6, applek...@gmail.com wrote:
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> > > > Hi everbody,
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> > > > I'm Bryan Gates and NO I'm not related to Bill Gates lol.
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> > > > I'm new here and there are a lot of good post on here.
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> > > > I recently read the cookiecritters post about the LemminGS
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> > > > Source Code and I have downloaded it from brutal deluxe site.
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> > > > I have the same problem. I'm not that good in assembly but
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> > > > I know how to assemble and link. I will give anyone a Free
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> > > > Real Apple II GS with 100 Disk 4 Disk Drives, Hard Drive
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> > > > and an Apple Works II Printer with extra ink to remove
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> > > > the protection within the source code. and then send me
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> > > > the modified 2mg source code image.
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> > > > If you're interested reply back on here.
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> > > > I'm in the Central Time Zone Area and it's
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> > > > 10:33pm here but I'll be up all night and will
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> > > > check this post all night.
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> > > > Thanks for your time,
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> > > > Best Regards,
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> > > > Bryan Gates
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> > > I'll do it for free... or at least for a //gs expansion ram card. (no, kidding, I'll do it for free really)
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> > > This is a guess because 1) I don't speak French and 2) I don't feel like compiling everything to verify it but:
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> > > 1) Open LEMMINGS.MAIN.S
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> > > 2) Replace lines 1694-1726 with the following:
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> > > VERIFCHECK CLC ; TOUT EST OK
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> > > RTS
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> > > -B
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> > HI there, Is that replace lines 1696 through 1726 or just line 1696?
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> > I tried but It didn't work. I'll give you any parts you want if you can
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> > do it and send me the 2mg file to verify it. I'll even throw in 2 GS Expansion Ram Cards.
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> > Please let me know ASAP.
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> > Thank you,
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> > Best Regards,
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> > Bryan Gates
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> Sorry -- that was a typo... 1694 not 1696.
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> Remove everything (and including) the line:
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> VERIFCHECK STZ VERIFCHECK3+1 ; LONGUEUR A VERIFIER
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> which should be 1694 all the way through (and also including) line 1726:
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> RTS
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> Then replace it with:
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> VERIFCHECK CLC
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> RTS
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> Theory of operation:
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> The fastest way to do a checksum is to XOR a set of bytes together, possibly doing some sort of manipulation along the way so that you get a different checksum for a set of 4 zeros than you would for a set of 5 zeros. At any rate, I just searched for "EOR" in the code which is the 6502/65816 opcode for XOR. It only appears in this routine. At the end, it appears to either set the carry bit (SEC) if the checksum doesn't match or clear the carry bit (CLC) if the checksum is OK.
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> Unless the source comments are intentionally misdirecting the reader (because obfuscation is fun), replacing the routine with a simple CLC (to clear the carry bit) and RTS (to return back) should gut out the CRC check. Thanks to Antoine for the hint about CRC. Indeed, having the source is very telling. The only other thing I can think of doing is padding the area with zero's to fill in the gap left behind. It really shouldn't matter though.
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> -B
Hi did you see my last post ?
Please Reply ASAP.
Thank you,
Bryan Gates