Steve Chamberlin over at Big Mess o’Wires has been working on an FPGA-based disk controller for Apple II, which he call Yellowstone: Apple II disk controller cards are weird, there are a crazy number of different types, and many are rare and expensive. Can an FPGA-based solution save the day for retro collectors? You bet! Nearly […]
Tag Archives: floppy emu
Lisa Native floppy emulation
Steve at Big Mess o’ Wires writes: Lisa floppy drive emulation with Floppy Emu is a success! Begone, evil rotational disk drives, with your failure-prone gummed-up mechanisms. The age of SD card Lisa floppy emulation is here! After a lot of tinkering, it’s now working on both the Lisa 2/5 and 2/10, and for both Lisa-format […]
Troubleshooting damaged chips
Steve at Big Mess o’ Wires writes: The most common failure I’ve seen is something I call “burnout”, and has affected about 4% of the units. After anywhere from one minute to a few hours of working normally, the Floppy Emu stops functioning, and both the 3.3V regulator and the CPLD become hot to the […]
Emulating the Apple HD20
Steve at Big Mess o’ Wires writes: So how does it work? First off, we can assume that raw data bytes are sent and received in serial fashion using NRZI encoding on the ReadData and WriteData lines of the floppy connector. While the DCD documents don’t specifically mention this anywhere, it’s a safe assumption because […]
Mac floppy emu prototype
Steve at Big Mess o’ Wires has resumed work on his Macintosh floppy drive emulator project. Previously he had developed the project on a breadboard using an Altera EPM7128S CPLD and an Atmel ATMEGA32u4 microcontroller. Now he has assembled it on a project board and updated some of his components. He writes: The firmware has […]