USB Apple ][ disk emulator

http://hackadaycom.files.wordpress.c...pg?w=273&h=200
One of the most commonly frustrating things about having an old Apple ][ lying around in your basement or attic is the lack of software. While at one time in the late 80s you may have had your own copy of Oregon Trail, that disk is either lost or non-functional, and it's pretty hard to get new disk images onto 5 1/4" disks.
To solve this problem for himself, [Eric] came up with an Apple disk emulator. A project like this has been done many, many times over the last few decades, but [Eric] put his own twist on it: he doesn’t use a microcontroller. Instead, he used a simple USB FTDI device to talk to the Apple disk drive.
The FTDI device in question is a UM232H chip that takes a USB connection and turns it into an SPI bus. Of course the Apple ][ disk doesn't speak SPI, so [Eric] needed to do a little logic conversion with a 74LS251 multiplexer and a 74LS161 counter.
In the video after the break, you can see [Eric] loading Apple disk images on a IIc from his new Intel Mac. It’s a neat build, but it’s not done yet: [Eric] plans on adding a microcontroller with an SD card, allowing just about every Apple ][ game every made to fit in your pocket. Yes, [Eric]‘s project is quite similar to the A][ pocket serial host we saw just a bit ago, but this will hopefully have a lower component count.

http://hackaday.com/2013/02/07/usb-apple-disk-emulator/