A true blank track is different than an empty/unused track. Copy-protected disks may have tracks that are truly blank, with no magnetic flux transitions. Even if there’s unused space on the disk, valid sectors will still be present – they’ll just be marked as unused. The track can even have fractional bytes, with a bitsteam size that’s not a multiple of eight.įake random bits (example: Print Shop Companion) – Normal floppies have data on every track. To avoid any possible confusion, WOZ stores each track as a single very long bit sequence, without making any assumptions about what the bits mean, or how many bits there are. Copy-protected disks throw all the standards out the window. Non-standard data (example: Rescue Raiders) – Normal Apple II floppy disks have 16 sectors per track, 256 bytes per sector, with a standardized sector header beginning with the famous D5 AA 96 byte sequence. The WOZ format addresses three major areas: I discussed Apple II copy protection techniques a couple of years ago here. Using disk images stored on an SD card, it can emulate 5.25 and 3.5 inch floppy disks, Smartport hard disks, Unidisks, and HD20-type hard disks. Many thanks to John for answering my questions and providing sample disk images for testing.Ībout Floppy Emu: Floppy Emu is an external disk emulator for classic Apple II, Macintosh, and Lisa computers. I was right about the time-consuming part, but wrong about the rest – I eventually found solutions to the technical challenges that worked on the existing hardware. But after a steady trickle of inquiries I finally took a second look at WOZ a couple of weeks ago, and was able to make it work. The Emu hardware doesn’t have enough RAM to pre-load a full disk image, so the idea looked like a non-starter, and I shelved it. I was skeptical that some of the timing requirements for cross-track synchronization and other WOZ featues could be met without pre-loading the entire disk image into RAM. WOZ format caught my attention when it was first announced last year, and I read through the documentation, but concluded it would be too time-consuming and difficult to add to the Floppy Emu. This includes software using copy-protection techniques like cross-track synchronization, intentional invalid or blank regions of the disk, and even the dreaded Spiradisc spiral data tracks. With the WOZ format, it’s possible for the first time to run heavily copy-protected vintage Apple II software directly from a disk emulator, without the need to “crack” the protection. Some formats like NIB come closer to capturing all the low-level details of the floppy data, but still fall short. These assumptions are fine for standard software, but they fail for vintage copy-protected software that intentionally violates the standards. Other disk image formats omit certain “unimportant” data like sector headers, or make other simplifications and assumptions about the disk data. Morris with the goal of being the most accurate possible representation of data encoded on an Apple II floppy disk. First released in 2018, it was developed by John K. WOZ disk image format is an exciting newcomer to the vintage computing world. WOZ disk images is now available on the BMOW Floppy Emu disk emulator! Steve on Floppy Emu Disk Emulator for Apple II, Macintosh, and Lisa.Race Fan on Yellowstone Universal Disk Controller for Apple II.Chris on Saleae Pro 8 Logic Analyzer Review.Yellowstone Universal Disk Controller for Apple II Floppy Emu Disk Emulator for vintage Apple II, Macintosh, and Lisa
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