Steve

Steve

Plans for a Yellowstone Tester

With Yellowstone hardware development hopefully approaching completion, I’ve started thinking more about the design for an automated tester. As long as I’m hand-assembling one board at a time, I can throw it in my Apple IIe and try exercising some…

floppy drive gears

Eject Motor Gearbox Autopsy

I disassembled the dead external floppy drive that I described in my previous post, and extracted the auto-inject SuperDrive mechanism that was inside. After carefully removing and opening the eject motor assembly, I discovered a gearbox with four plastic gears.…

floppy drive cable

Death of an M0131 Floppy Drive

Recently I bought an external 800K Macintosh floppy drive, model M0131, so I could confirm its compatibility with my Yellowstone disk controller card for Apple II computers. The testing didn’t go as planned, and now the drive is dead, but…

Disk Drive Testing

While I await the new Yellowstone v2.1 PCBs, I’ve been spending more time on testing. With my hacked-up v2.0 PCB, most things are working pretty well, especially with DOS3.3, ProDOS, or game disks. I can connect any odd combination of…

Back-Powering and Phantom Power From JTAG

Throughout Yellowstone’s development, I’ve struggled on and off with mysterious problems related to the JTAG programmer. When the programmer is connected to the Yellowstone card, and I turn the computer off and on again, strange things sometimes happen. The Apple…

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