nvm files?

can I read and change the files stored on nvm`s ?

basically I want to make/alter software changes on g3 accenta etc,

PC2400 programmer,or similar software has been advised,

Iam also using eprom files sub pro,which I can read the files and have identified the software changes,but it cannot rewrite nvm`s in standby mode.

Has anyone used the pc2400 software successfully,

your answers and input would be greatfully received,

thankyou.