The Epson PX-8 is a circa 1984 laptop computer, running the CP/M operating system (ROM based). Last I checked, you can still purchase new PX-8 systems from Star Technology. However, the PF-10 3.5" portable disk drive for the PX-8 is a very rare beast - the ones I've seen on eBay I've never been able to afford.
Communications between the PX-8 and PF-10 are over an RS-232 compatible connection at 38400 baud. The protocol is documented, and there are a couple of software packages - one for Linux, and one for DOS - that emulate the drive. I would like to extend the work that's already been done in this field, and create a portable, battery-operated virtual disk drive for the PX-8.
I'm hoping to be able to use a Propeller microcontroller chip as the "brains" of the virtual drive. The Propeller is cool - 8 parallel cores or "cogs" typically running at 80 MHz nominal clock speed. There are hardware/software solutions for interfacing with external storage, including SD cards.
Like last year, I've entered the Retrochallenge contest with the goal of producing a first pass at a virtual drive prototype. Unlike last year, this year I hope to achieve the goal!
More postings as I go. Look for details on this blog, with the tag label "retrochallenge".