Apple II

Apple II Card Electrical Woes

February 12, 2018 Big Mess o' Wires

The digital abstraction of zeroes and ones is lovely, but electronics debugging often requires a deeper look into the realm of analog signals. That’s the story of my Yellowstone FPGA-based disk controller for Apple II, and it’s slowly driving me crazy. Those nice clean zeroes and ones are gone,

Apple II

Mac ROM-inator II Sale!

February 9, 2018 Big Mess o' Wires

Want to add new features to your old Mac? The Mac ROM-inator II hardware for vintage Macintosh is on sale at a special price for a limited time. The ROM-inator II SIMM replaces the stock Macintosh IIx, IIcx, IIci, IIfx, IIsi, or SE/30 ROM with a programmable flash memory

Apple II

Yellowstone Bugs

February 5, 2018 Big Mess o' Wires

I’ve discovered a troubling problem with the Yellowstone disk controller for Apple II, and I’m unsure how to debug it. When it’s functioning as a Liron clone, Yellowstone isn’t playing nicely with other cards like a stock Disk II controller card. While booting from a Prodos 1.9 disk image

Apple II

No Device Connected

January 30, 2018 Big Mess o' Wires

Finally, the first real progress on the Yellowstone disk controller since last summer! Sometimes an error is a good thing. It doesn’t look like much yet, but this error demonstrates that the Yellowstone card is correctly decoding address references to its slot, and is serving up data from a

Apple II

What’s on the BMOW Bookshelf

January 20, 2018 Big Mess o' Wires

Over the decades, I’ve pared my collection of books down to just four shelves – only about 100 volumes from a lifetime of reading and studying. Because who needs physical books in an age where everything is available online? The few books that remain in my collection have survived a

Apple II

Yellowstone JTAG Debugging

January 17, 2018 Big Mess o' Wires

After a month of inactivity, I finally returned to my unfinished Yellowstone disk controller project to investigate the JTAG programming problems. Yellowstone is an FPGA-based disk controller card for the Apple II family, that aims to emulate a Liron disk controller or other models of vintage disk controller. It’s