Improved techniques for calculating decision parameters in an IMT-2000 system, the IMT-2000 system having a mini-slot selection unit for selecting a mini-slot position wherein a decision parameter is selected and a decision parameter selection unit for selecting one decision parameter from the calculated decision parameters, is disclosed. The attachment device has a base for surrounding and attaching around the opening in the top cover in the disc drive and a centrally located aperture for communicating with an upwardly extending flexible tube. The male connection member of the railway coupling device includes an aperture having a predetermined configuration and an inner surface formed by this aperture. Retracting the writing surface may include rolling the writing surface onto a spool, accordion folding the writing surface or otherwise reconfiguring the writing surface to make it fit into a compact space.