Data transfer to and from logging while drilling tools

A system transfers data to or from a logging tool adapted for drilling operations within a subsurface formation. The system comprises a logging tool 19 adapted to make measurements while drilling through subsurface formations. A memory module 29 housed within the tool is adapted to record and store data related to these measurements. The memory module is also adapted for retrieval from the tool, and for coupling to a data processor (fig 5, 37). The memory module can transfer data to and from the data processor. The memory module may also be interrogated by the logging tool for drilling parameters.