Sunday, December 29, 2013

Getting ready for Retrochallenge 2014 Winter Warmup

Hey there,

I'm beginning to pull together the materials and skillz needed to complete my entry for the Retrochallenge 2014 Winter Warmup.

My entry this time is a rerun. Once again, I seek to create a solution for an Epson PX-8 virtual disk drive, but with a twist. To recap the background and goals:

  • The Epson PX-8 is a laptop computer produced in the mid-80s. It has CP/M 2.2 in ROM, and an 80 by 8 bitmapped LCD display. It's a cute little laptop. (I used to be on the tech support team, hence my nostalgic love of the device.)
  • There are many brand-new PX-8 computers in the wild right now, thanks to the sales of NOS from Star Technology in Aurora, Colorado. Sadly, they are out of stock now, but many PX-8s made it out there, and are looking for a floppy device :-)
  • The original floppy solution for the PX-8 back in the day was the PF-10 portable disk drive. Even when the PX-8 was new, these drives were rare. I had one because I worked at Epson. But most people didn't. These days, a few people have them, but they are basically unobtainium. Check out some nice images on this blog post.
  • The PX-8 and PF-10 talk to each other over a defined protocol, and using a simple RS232 serial link at 38400 baud. This lends itself to emulation. A couple of software solutions are out there for emulation, including the recently-updated vfloppy software by Fred J Kraan.
  • Originally, I had considered writing software for the Parallax Propeller to emulate the drive, using published materials and the open-source vfloppy software as a guide. However, when the Raspberry Pi Linux-capable SBC came out, my thoughts changed. It seemed like a good idea to use the vfloppy software as-is, or perhaps with a few modifications, and the Raspberry Pi as the platform.
  • Turning the RasPi into a standalone appliance seemed like a challenge - you either need a full keyboard/mouse/monitor, or you need to terminal into the Pi somehow. However, add-ons to the rescue. PiFace makes an add-on for the Raspberry Pi called the Control and Display unit. It's awesome! It's a 16x2 backlit LCD with buttons and a rocker control, and it fits right on top of the Raspberry Pi, connecting to the GPIO pin headers. This allows local, finger-press control of the Pi without a full console setup. With this, I believe I can tweak the vfloppy software and make an appliance-style virtual drive for the PX-8. It still won't be battery-powered (yet), but it will be small, self-contained, and functional.
That's my plan. This time for sure!