I have a question about RMS...apart from the record id what is the limit of the number of fields allowed for a given record? From the sources I have read I have the impression that there are only 2 fields allowed (including the record id).
MIDP RMS doesn't impose any size limit or number of fields to each record. This means that each record has just the recordID and record contents as an unstructured byte array available to the program. Internal structure of a record is up to the programmer.
Normally you would create a ByteArrayOutputStream and a DataOutputStream. Then you just write the info in one of the basic types using writeInt, writeUTF, etc. methods. You read it the same way using ByteArrayInputStream and DataInputStream.