My very first computer was a Panasonic JR-100, sort of a cross between a ZX-81 and a Spectrum. If you're not familiar with this home computer then you can read more at http://www.old-computers.com/museum/computer.asp?st=1&c=320 (I contributed images and info to this page). I've still got my old JR-100 and it's in pretty good condition (the box is a little bit worn and the manuals are also worn with all the use I them to while learning to program).
A year ago I was approached by someone working on the MESS (Multi Emulator Super System) project. They wanted to emulate the JR-100 and managed to track me down as an owner of this old computer. He wanted me to provide a dump of the ROM for the emulator. After much playing around I managed to hook the JR-100's cassette port up to the sound card in my PC and record a save file of the ROM. I then used some software I found to convert the WAV file into binary that could be used by the emulator.
The emulator mostly works, although the last time I looked at it the keyboard mapping wasn't the greatest and could be improved upon.
Does anyone else have a JR-100? Are they considered to be fairly rare? I once mentioned it on the Retro Gamer magazine forums and nobody there had ever heard of it. From what I understand they were only ever sold in Japan and New Zealand (maybe Australia?) The JR-200 was more widely sold in the USA.