Squeak,
The model you are referring to is the SK-900, an attempt by Suzuki in the mid 90's to produce an arranger/synth. Poor and short-lived, there are a few around. If you want specific info or need parts, contact Nick at 1-800-854-1594. The SP series that DJ lead you to are the current portables. The SP-77 was introduced a year ago at NAMM and is still yet to be released. That one has after-touch and a mic input, etc, but for the money, it's pretty lame.
zuki