Monday, February 15, 2021

The .woz Format - Accurate Preservation of Apple II Floppy Disks

The need for proper preservation of floppy-based software cannot be understated.  Floppy disks were not designed to store data for forty plus years, but for the oldest home computer systems like the Apple II, most of its software is at least thirty years old.  But it is not preservation merely to dump a copy of a game which was pirated in the day.  Those games usually have "cracktros" which do not represent the developer's intended presentation of the game, may have cut out elements of the original game to save space or may include corrupt data in them.  Ideally one should have a proper image of original disks with all data preserved.  Of course, from almost the earliest days of the Apple II's Disk II drive, copy protection schemes were implemented on commercial software to prevent casual disk copying.  True preservation requires preserving them as well, and that requires emulation to become more accurate than it needed to be for just sector based .dsk images.  In this blog article I will describe in as much detail as I can how the Disk II Floppy Drive works, how it is different from floppy drives for other systems, how data is stored on disk, the benefits of the .woz format and how .woz images are made.

Friday, January 22, 2021

wDrive v. Floppy Emu - Comparison of the Best Apple II Disk Emulators

The 5.25" floppy disk was the principal medium of program storage for the Apple II series of computers.  Thousands of software titles were written specifically for the Apple II's Disk II drive and its successors and clones.  Using floppy disks, and more specifically disk images, is essential to using an Apple II computer.  To use a disk image is to either write the image back to a disk, a cumbersome and sometimes unreliable process, or use a disk emulator.  In a recent past blog article, I have written about the Floppy Emu, a very capable Disk II drive emulator.  I have recently acquired the wDrive, another emulator device which can simulate a Disk II drive.  While similar to the Floppy Emu in many ways, the wDrive has its own benefits and quirks, and here I will compare the two hardware floppy emulators.