Search found 12 matches

by NewRisingSun
Fri Dec 23, 2016 10:13 pm
Forum: SuperCard Pro Disk Copier
Topic: SCP disk images !
Replies: 571
Views: 246810

Re: SCP disk images !

So, I can run the troublesome SCP image if I decode from the end of rev0 over the index signal into rev1, then keep the original track length by rotating the buffer by the number of bits between the index signal and the first write splice. I detect the write splice by looking for three zero bits in ...
by NewRisingSun
Fri Dec 23, 2016 8:35 pm
Forum: SuperCard Pro Disk Copier
Topic: SCP disk images !
Replies: 571
Views: 246810

Re: SCP disk images !

Not that I know of. And I don't know how a size code of 0x2E would be interpreted, as these sectors are never read by the keydisk checking routine anyway. My guess is that they're just there to fool copiers. The keydisk checking routine only reads three sectors in the following order: ⋅ 0-...
by NewRisingSun
Thu Dec 22, 2016 5:08 pm
Forum: SuperCard Pro Disk Copier
Topic: SCP disk images !
Replies: 571
Views: 246810

Re: SCP disk images !

so there should never be any type of problem getting the same data start position every time you read a revolution. The time factor (track duration) will change due to drive speed warble, but the index trigger is consistent. Well, I have your word, and my own experience with Kryoflux images, agains...
by NewRisingSun
Thu Dec 22, 2016 4:24 pm
Forum: SuperCard Pro Disk Copier
Topic: SCP disk images !
Replies: 571
Views: 246810

Re: SCP disk images !

JimDrew wrote:The information about the first/last bitcell time split should be obvious to anyone that would be writing software that deals with flux data.
It's not obvious to me, and Ijor thinks that treating any particular revolution as a circular buffer would fail because of jitter.
by NewRisingSun
Thu Dec 22, 2016 1:26 pm
Forum: SuperCard Pro Disk Copier
Topic: SCP disk images !
Replies: 571
Views: 246810

Re: SCP disk images !

Well, let's just wait for Jim's response, then. :) In the meantime, if you have the time, could you please take a look at the same FTP server, file "/SCP/IBM-PC/[SCP-IBM PC] JOE & MAC CAVEMAN NINJA (ELITE SYSTEM - EURO version) - IBM PC - (C) 1991 DATA EAST - ELITE SYSTEM LTD.7z"? I ca...
by NewRisingSun
Thu Dec 22, 2016 12:57 pm
Forum: SuperCard Pro Disk Copier
Topic: SCP disk images !
Replies: 571
Views: 246810

Re: SCP disk images !

So the reason that it always worked with my Kryoflux images is that my drive is very accurate, while the drive used to make that Boulder Dash 1 SCP image is not that accurate? I still need an explanation that accounts for that. Maybe Jim can add another two cents here.
by NewRisingSun
Thu Dec 22, 2016 12:34 pm
Forum: SuperCard Pro Disk Copier
Topic: SCP disk images !
Replies: 571
Views: 246810

Re: SCP disk images !

Well, with Kryoflux images, my approach has worked for every single image so far that uses sector-spanning protections --- I count eight such images that I imaged myself, too many for me to just have been lucky ---, so I beg to differ. Btw, the people behind the Kryoflux agree with what I just said....
by NewRisingSun
Thu Dec 22, 2016 11:59 am
Forum: SuperCard Pro Disk Copier
Topic: SCP disk images !
Replies: 571
Views: 246810

Re: SCP disk images !

That, and because I am converting between file formats, including to those that can store only a single revolution, such as TransCopy or PRI. And given that it works perfectly with Kryoflux sources, it should work with SCP sources as well.
by NewRisingSun
Thu Dec 22, 2016 6:17 am
Forum: SuperCard Pro Disk Copier
Topic: SCP disk images !
Replies: 571
Views: 246810

Re: SCP disk images !

Well, as I said, I could decode sector 11 across the index "correctly". Take a look at page 14 of the "Kryoflux Stream Protocol V1.1". That explains exactly how the index times (which I assume match the "duration" field in the SCP track header) are to be interpreted re...
by NewRisingSun
Thu Dec 22, 2016 3:04 am
Forum: SuperCard Pro Disk Copier
Topic: SCP disk images !
Replies: 571
Views: 246810

Re: SCP disk images !

To be more precise about what the protection is looking for: from what I can tell (*) it counts the number of identical bytes at the beginning of the sector and uses the resulting count as part of a decryption key. (*) The protection uses the Trace vector decoder method of obfuscating its code, so i...
by NewRisingSun
Thu Dec 22, 2016 2:48 am
Forum: SuperCard Pro Disk Copier
Topic: SCP disk images !
Replies: 571
Views: 246810

Re: SCP disk images !

So I don't know exactly what the protection expects from that sector. The keydisk checking code expects the sector to be as decoded from the Kryoflux image which you already wrote you had taken a look at. If there is a way of decoding the SCP image to yield that result, then it is a question of int...
by NewRisingSun
Wed Dec 21, 2016 11:31 pm
Forum: SuperCard Pro Disk Copier
Topic: SCP disk images !
Replies: 571
Views: 246810

Re: SCP disk images !

Is he asking me? I'm not sure who I'm talking to anymore. "coolhaken" PMs me on the vogons.org message board saying that he's got an SCP image that doesn't work in the experimental build of DOSBox that I sent him, which supports protected disk images. I ask him questions about where the i...

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