.SCP files usage in WinUAE
Just tried .SCP support in WinUAE Public Beta 11..
what can I say.. it's A-W-E-S-O-M-E !!!!!!!
thanks to whoever implemented it and thanks to Jim.. Now it's a breeze to play also my originals in WinUAE.. just a few seconds to image.. and it's done..
tried with Ballistix and Alien Breed.. worked flawlessly.. I think this is a very *NICE* addition to WinUAE..
All the credit goes to Keir Fraser. He stepped up and offered to do the support, and in just one day it was working. Keir also has worked in support for the SuperCard Pro board into his analyzer/converter.

I am testing a new image mode for "emulation" images. This mode is not a "preservation" quality because the flux data is run through a DSP type filter making it not 100% exactly the same, but all protection schemes still work. The advantage of this mode is that images compress to just 5%-10% of their original image size! Since UAE can use 7 zip files, you can compress the image files and leave them that way. You can also use these images to write disks, but if are concerned about having the disk image 100% authentic (as opposed to just working) you can opt not to use the new mode.
This, in my opinion, would render ADF format obsolete.. for now ADF only advantage is size of the image files that is much less.. but if we can have at roughly the same size an image that works also for protected games that would be a killer Big Grin

So many thanks to Keir Fraser and anyway to you also, Jim, for implementing the card..
With the preservation mode disabled, image files can be compressed dramatically. For example, Space Station Oblivion (which uses a nasty variable density protection) is about 13MB as a flux image. In preservation mode, the image compresses to ~3.2MB. In non-preservation mode, the image compresses to ~880K. Both versions work fine under the emulation, and both versions actually write to disk correctly - although it's not a guarantee with the non-preservation mode image.
Thanks, I have a tiny bit more work to do to correctly support weak bits and no-flux areas. But these protection types are incredibly rare on Amiga anyway. Apart from a few games using such protection types, all Amiga disks should work with the existing WinUAE SCP support.
Weakbits apparently works fine. Turrican II works, and it has weakbit protection on track 0, head 1.

I don't have any originals with no flux areas. I know that Ivanhoe has this protection, but when I bought a disk from a seller in the U.K. I learned (from looking at the disk) that it is a copy that has a parameter run on it. The disk is identical, but the protection check always passes no matter what is on the protected track. I have noticed a LOT of disks coming from the U.K that have silkscreened labels. Some of the original disks were this way, but most were not - and these "originals" have silkscreened labels and have NO copy protection on them - but contain the normal AmigaDOS data in the exact same spot - just a protection bypass. These are copied on a commercial duplicator though, perhaps one of the little single disk units.
This is true, the UAE support will already work well for multi-revolution dumps as most protection checks are only across a few spins of the track. But I plan to add support for single-rev dumps and also for protections which check many more spins of the track. Purely by randomising bitcells at the edge of the timing window, or during long period of no flux.
Single rev dumps with weakbits are all I have tested, and those work fine. Likely because an odd number of bitcells are present, so from read to read the data should change.
Well that's handy. Maybe I'll wait to test a game that actually doesn't work! Big Grin
I have not found a single game that does not work. However, I have only tested a few hundred of the most heavily protected games, not everything made.

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