question for datawiz (let's solve the Chessmaster 2000 mystery)

qkumba

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Aug 14, 2014, 3:25:05 PM8/14/14

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Regarding your Chessmaster 2000 crack, and the resulting issue with AppleWin - what kind of machine did you have at that time, or was it targeting an emulator?
The check for $c1 at $fb09 is not a protection, it's a valid platform detection, and it's really needed for a real Apple.

datawiz

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Aug 14, 2014, 5:32:09 PM8/14/14

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On Thursday, August 14, 2014 3:25:05 PM UTC-4, qkumba wrote:
> Regarding your Chessmaster 2000 crack, and the resulting issue with AppleWin - what kind of machine did you have at that time, or was it targeting an emulator?
>
> The check for $c1 at $fb09 is not a protection, it's a valid platform detection, and it's really needed for a real Apple.

qkumba,
File create date of 1997-- 17 years flies by in a blink...
Around that time, I would have tested it on a ROM01 IIgs and targeted it for an emulator-- either AppleWin or ApplePC. At that time, I preferred AppleWin for it's debugger.

I see what you are saying-- I booted it up in Virtual ][ and it soundly crashes. Perhaps you've tried-- have you rolled back the changes i put in the .txt file to the original bytes to see if that permits it to run?

Rich

datawiz

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Aug 14, 2014, 5:38:56 PM8/14/14

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> I see what you are saying-- I booted it up in Virtual ][ and it soundly crashes. Perhaps you've tried-- have you rolled back the changes i put in the .txt file to the original bytes to see if that permits it to run?
>

Answered my own question-- patching it back in does allow the image to run correctly. Fortunately, I made notes. :) I would imagine that I mistook that when it failed to run in apple win circa 1997 and figured that out by using the debugger.

qkumba

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Aug 14, 2014, 6:42:57 PM8/14/14

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> Answered my own question-- patching it back in does allow the image to run correctly. Fortunately, I made notes. :) I would imagine that I mistook that when it failed to run in apple win circa 1997 and figured that out by using the debugger.

Indeed it does, as does the untouched .nib.
So unfortunately the mystery remains unsolved, since we still don't know which machine required the check to fail, so that the track numbers would be updated.

sicklittlemonkey

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Aug 14, 2014, 6:47:05 PM8/14/14

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On Friday, 15 August 2014 09:38:56 UTC+12, datawiz wrote:
> Answered my own question-- patching it back in does allow the image to run correctly. Fortunately, I made notes. :) I would imagine that I mistook that when it failed to run in apple win circa 1997 and figured that out by using the debugger.

Timing ... I just figured this out last night thanks to Peter realising it was a problem with the image, not my stepping code in AppleWin. ; - )

Here's what I just added to the AppleWin "bug" that was logged:

"Datawiz put an email address in his crack "Tech Notes", and the dates inside the zip are 1997. So because it's a modern era crack he would have been using a IIgs (like I did in the 90's), and the IIgs doesn't leave phase 0 on after booting slot 6. The GS happens to fail the clone check though, because $FB09 has changed, so it would have crashed on the GS without disabling the clone check."

My hypothesis is that the check is there to enabled the game to work on the Laser series of clones. Surely the Franklins would have worked because they just copied the Apple ROMs. I'm guessing the Lasers don't leave phase 0 on either, and so would have failed without the check. I'm yet to confirm that ...

Cheers,
Nick.

Antoine Vignau

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Aug 14, 2014, 6:57:48 PM8/14/14

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This is the IWM (or post-Disk II) which has integrated/modified the phase 0, not the IIgs (but, as the IWM is in the IIgs...)
That thing was known to Apple for many years, read the IWM section at http://www.brutaldeluxe.fr/documentation/iwm.html

Sirius Software, in the early 80's, turned off phase 0 for security/safety, as it was recommended by Apple.

I'm pretty sure this is the reason why the spiradisc floppies do not boot well on a IIgs with no Disk II controller card...

Antoine

Vladimir Ivanov

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Aug 15, 2014, 5:10:47 AM8/15/14

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On Thu, 14 Aug 2014, Antoine Vignau wrote:

> This is the IWM (or post-Disk II) which has integrated/modified the
> phase 0, not the IIgs (but, as the IWM is in the IIgs...)
> That thing was known to Apple for many years, read the IWM section at
> http://www.brutaldeluxe.fr/documentation/iwm.html

Toto, what exactly do you mean by "IWM .. integrated the phase 0"?

Some of the differences between the discrete disk controller and the IWM
are listed here:

http://www.brutaldeluxe.fr/documentation/iwm/iwm_discussion_19820531.pdf

> Sirius Software, in the early 80's, turned off phase 0 for
> security/safety, as it was recommended by Apple.

The only two concerns I have seen about leaving PH0 (or any phase) on are:

1) degraded read data due to head oscillations. Practice shows this is no
concern and is probably offset by the wide enough head.

2) eventual stepper motor coil overheating. Haven't heard of such a case.

And maybe the very general screwing up the expectations of any RWTS if it
does not reset all phases first.

> I'm pretty sure this is the reason why the spiradisc floppies do not
> boot well on a IIgs with no Disk II controller card...

This is something interesting. Are you sure it is not because of using
parts of the $C6xx ROM?

Does it mean that they sometimes work and sometimes don't?

sicklittlemonkey

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Aug 15, 2014, 9:57:48 AM8/15/14

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On Friday, 15 August 2014 10:47:05 UTC+12, sicklittlemonkey wrote:
> "... the IIgs doesn't leave phase 0 on after booting slot 6. The GS happens to fail the clone check though, because $FB09 has changed, so it would have crashed on the GS without disabling the clone check."

Correcting myself for necro-readers from the future:

I've forgotten so much about the GS I better be careful what I say. FF/FB09 is still C1, so the clone behaviour doesn't apply, and phase 0 is left on in the GS by its equivalent of boot zero. My previous statement was inferred from behaviour, and using GSport was not a good test!

I thought it was datawiz's GS that didn't work and that prompted the patch (EA EA) because GSport crashes with the original (F0 12) image. But he was using an old version of AppleWin, and I just tested on real hardware, so the summary is ...

Platform Original (F0 12) Patched (EA EA)
AppleWin (old) Fails Works
AppleWin (now) Works Fails
GSport Fails Works
ROM 3 GS Works Fails
ROM 4 //c Works Fails

And the mystery is still which clone the FB09 test was for.

Cheers,
Nick.

Antoine Vignau

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Aug 15, 2014, 11:06:06 AM8/15/14

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emulator accuracy...
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