I am not sure if SDK 2.1 is the proper tool for above phones. When I installed the sw, it was not able to detect any of these, I am using the DAU-9P cable. If somebody could help me I would really appeciate it.
RE: SMS for 6120 / 5120 tdma phones
There was no mentioning about connectivity to PC with these phone
models. AT-commands would have beeen another option to SDK but they
don't seem to be implemented in these phone models either.
M, Forum Nokia