An FPGA-based disk controller card for the Apple II family.
The goal of a “do everything” disk controller for Apple II is getting closer to reality, thanks to the efforts of the hard-working beta testers. If all goes well, I’m hoping to have Yellowstone cards available for sale in the…
In the world of Apple II disks, there are two major types of disk controller cards: the original Disk II controller (and clones), and everything else. Both have their place. The “everything else” category includes the Apple 3.5 disk controller…
Here we go! Beta testing kicks off today for the Yellowstone universal disk controller for Apple II. Yellowstone is a replacement for the Liron disk controller, the Apple 3.5 disk controller, and the standard Disk II controller, all rolled into…
In my attempts to resolve some logic level problems with the Yellowstone Tester, I decided to take a crude approach, and reduce the 5V supply to about 4.7V using a simple zener diode voltage regulator. From my previous tests with…
The Yellowstone tester is suffering from the logic level blues. I made a blundering error in its design, which I only discovered now. Like most of my projects, the tester uses a mix of voltages, with the MCP23S17 port expanders…
I once said I’d spend a maximum of one day on development of an automated tester for the Yellowstone disk controller. Haha, that was so cute. Today marks two months since I began work on the tester. Today was also…
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