A method of coordinating operations performed by a host section and an engine section in a mobile telecommunications terminal in order to enable the engine section to utilise at least one functional device (24, 25MB, 27, 28), where the host section is configured to perform communication operations, and the engine section is configured to perform application program operations and the at least one functional device (24, 25MB, 27, 28) is connected to the host section, the method including: operating the engine section in an engine mode when the engine section is performing application program operations, or otherwise operating the engine section in a host mode; a host processor of the host section managing access by the engine section to the at least one functional device by: the host processor receiving a request from an engine processor of the engine section to operate a specific functional device of the at least one functional devices (24, 25MB, 27, 28); upon receiving the request, the host processor performing an operation control process including: determining a mode in which the engine section is operating; where the engine section is operating in the host mode, the host processor terminates the operation control process; where the engine section is operating in the engine mode, and the host processor determines that the engine mode state is to be continued then the host processor operates the specific functional device in accordance with the request. operating the engine section in an engine mode when the engine section is performing application program operations, or otherwise operating the engine section in a host mode; a host processor of the host section managing access by the engine section to the at least one functional device by: the host processor receiving a request from an engine processor of the engine section to operate a specific functional device of the at least one functional devices (24, 25MB, 27, 28); upon receiving the request, the host processor performing an operation control process including: determining a mode in which the engine section is operating; where the engine section is operating in the host mode, the host processor terminates the operation control process; where the engine section is operating in the engine mode, and the host processor determines that the engine mode state is to be continued then the host processor operates the specific functional device in accordance with the request. the host processor receiving a request from an engine processor of the engine section to operate a specific functional device of the at least one functional devices (24, 25MB, 27, 28); upon receiving the request, the host processor performing an operation control process including: determining a mode in which the engine section is operating; where the engine section is operating in the host mode, the host processor terminates the operation control process; where the engine section is operating in the engine mode, and the host processor determines that the engine mode state is to be continued then the host processor operates the specific functional device in accordance with the request. determining a mode in which the engine section is operating; where the engine section is operating in the host mode, the host processor terminates the operation control process; where the engine section is operating in the engine mode, and the host processor determines that the engine mode state is to be continued then the host processor operates the specific functional device in accordance with the request.