John Morris, the developer of Applesauce device has added support for 3.5″ drives and also released sync-sensor for the drive to be used. Applesauce client v1.1 was released in (5.5.2019) and it supported fully the Apple 3.5″ drive, reading and writing back to the disk.
It’s easiest to follow the teardown instructions by ifixit.com
The sync-sensor is installed next to the spinning wheel of the 3.5″ drive in bottom. The idea is the same, basicly the sensor reads the magnet strip that is installed to the spinning wheel for more accurate location of the disk.
There is room for the sync-sensor cable to route if out of the case along with the connector cable.
I had only few original 3.5″ (Apple IIGS) floppies so i chose the “Marble Madness” that i had in hand. I first read the .a2r flux image out of the disk and then made .woz out of it (analyze and save). The .woz file then can be written back to blank disk.
I booted the written copy with my IIGS (ROM3) and it worked perfectly. Pretty amazing!
“Marble Madness” (GS) – without the sync-sensor installed vs with sync-sensor installed (both booted).
John Morris about the copy protction at twitter:
“Marble Madness has an “impossible to copy” track at $20 side 1 (400+ nibbles too big) that was clocked in a way that the IIgs couldn’t write out. Applesauce detects the abnormality and re-clocks the write on the fly. This exact protection scheme proved to be so effective that many competing publishers adopted it. It evolved a bit over the years, but largely remained the same. It is structured in a way that sector copiers think they copied it, but the sectors were actually just a decoy”.
This shows how genious the Applesauce client (and John) really is!
Applesauce can be bought from:
FinApple 2019 (c)
Apple II Forever.