Wednesday, January 30, 2013

RetroChallenge 2013WW Review

This has been a fun month. I am really excited that I completed one project and hopefully provided a useful tool to the Apple II community.

Disk ][ Emulator: I just uploaded the USB AII-SPI-DSK executable and schematic. The binary is compiled for x86_64.

AII-SPI-DSK project source code is now available too. The code requires user to have libusb, libftdi and libmpsse already compiled and installed. Once you get past the Xcode project format, the code should be pretty portable to other platforms. Most of the coding was done fast and dirty, so please excuse the unavoidable errors.

The USB AII_SPI_DSK Disk ][ Emulator is by far my most complex electronics project I have ever taken on. Fortunately, the Apple Disk ][ controller card is pretty flexible with the input it can take, or I would have never completed this.

I didn't quite reach my lofty goals on this project, but I did end up with a good proof of concept and a handy device in its own right. And, because this project uses a standard SPI stream, I should be able to easily create a micro-controller based solution that actually uses an SD card! The Retro icing on the cake for this project is using 2 ICs recycled from an old Apple II+ for my build.

Apple IIe Platinum: Living a new dust-free life.

Apple IIGS: Still rusty and in pieces. A little closer to living though.

Apple //c: Still neglected with 255 ROMS. I didn't even get to think about this project.

Take a minute to check out the RetroChallenge website and see what the other participants worked on.


  1. I'm curious, will this work with 2mg images? I'm looking for something like this for my IIgs

  2. I am very interested in this project. So, basically you are emulating a Disk II by means of software on a Mac? Sort of like a file/disk image server?

    I've been interested in doing something similar to this where, with a simple interface, you can connect an Apple II system to a USB port on a PC or Mac and using a server application, you can map disk images to up to four virtual disk drives, or swap them out on the fly if you need to. Possibly also provide some hard disk emulation through the Smartport.

    From what I can gather in your video, this is more of less what you have done here. Is that correct??

    1. Joaquin,
      Some of the emulation is done by the electronics and some by the Mac. The Mac is just sending parts of a disk image to the USB hardware. The hardware makes sure that it is in a format the Apple II disk controller can read. The benefit of this project is that it uses a standard SPI serial stream which gets slightly modified for the Apple II. Most AVR microcontrollers have dedicated SPI pins.