Posts: 3,283
Threads: 104
Joined: Jul 2005
The VX-4 was never released outside Japan. It's an educational model and therefore all the docs are in Japanese. You can get some useful information from studying the manual of a PB-1000 or FX-850P (the latter is closer to the VX-4). Since I have a VX-4 in my collection, its BASIC is part of my BASIC comparison sheet. You should find enough info there to make use of your VX-4.
http://www.mvcsys.de/doc/basic-compare.html
If you have questions, don't hesitate to ask here.