I am looking for a MIDI file conversion software that converts MIDI format 1 to MIDI format 0--the only format which my Casio WK-1800 reads, and still keeps multiple tracks. I had found one on the web a year or so ago that was great, but lost it when my hard disk crashed and now it's no longer posted on the web. I've tried other downloadable converters, but they all send all tracks to a single track when converting format 1 to 0. Can anyone help? I'll be grateful for some input.

I did a search on google.com for you. This link appears suitable for a FREE download.
http://www.gnmidi.at/gnfreeen.htm

If not, do another search on www.google.com
enter midi format 1 to 0

Graham UK