Abstract: A separation type feature expanding device comprises an attachment device comprising a bottom supporting flat portion on which a notebook personal computer is mounted, and a port replicator portion provided in a rear end of the bottom supporting flat portion and having a terminal portion to which a terminal portion provided on the back surface of the notebook personal computer is removably connected, and a feature expanding unit containing one or more feature expanding devices of the notebook personal computer, having its upper end surface on which the bottom supporting flat portion in the attachment device is mounted, and having a terminal portion to which the terminal portion of the port replicator portion in the attachment device is removably connected.

Abstract: A separation type feature expanding device comprises an attachment device with a bottom supporting flat portion on which a notebook personal computer is mounted, and a port replicator portion provided in a rear end of the bottom supporting flat portion and having a terminal portion to which a terminal portion provided on the back surface of the notebook personal computer is removably connected, and a feature expanding unit of the notebook personal computer, having its upper end surface on which the bottom supporting flat portion in the attachment device is mounted, and having a terminal portion to which the terminal portion of the port replicator portion in the attachment device is removably connected.

Abstract: An automatic release device for automatically releasing hold-on setting of an outside line call wherein a first telephone when having an outside line call from a second telephone and set to the hold-on state can be released from the hold-on setting by use of a sensing means detecting signals based on the hook-down at the second telephone slde. Further a transfer method for an outside line call, by using a conference call system served by Telegraph and Telephone Corporations wherein a running outside line call received from a second telephone by a first telephone through outside line wire is set to enable the conference call and the first telephone is set to the hold-on state so as to allow persons at the second and third telephones to talk with each other, wherein a sensing means for detecting signals based on hook-down of either of the second and third telephones is used to release the first telephone from the hold-on state.