Abstract: A computer (10) is provided with a casing (12) which includes a component mounting system (18) for mounting a component (16) within the casing (12). The system includes a component support (22) securable to the casing (12); a plurality of posts (44,46) mounted on at least one sprung member (48), which is mounted to the support (22). The posts (44,46) are operable to be engaged in at least one associated recess in the component (16) and are movable between a component engaging position and a component non-engaging position. A slider (28) is slidable relative to the posts (44,46) and is operable to move and retain the posts (44,46) between the component engaging position and said component non-engaging position. A component can be removed and fitted into the computer (10) easily even by an untrained user.

Abstract: To facilitate user installation of units in a computer, a clamping lever arrangement is provided which can be tightened by an external screw to clamp in position one or more units internal to the housing. In one arrangement, the clamping lever is provided with four fingers that pass through respective apertures in the computer housing. Each finger serves to clamp in position a respective expansion card, or blanking plate if no card is present. Thus a single clamping lever with a single external fixing screw replaces the standard usage of a respective fixing screw for each card.

Abstract: Hard disc drives for desktop computers are standardly available in two different sizes. A mounting tray is provided enabling the mounting of either size of unit in the same space without the need for different mounting pieces. The mounting tray includes two stepped side members provided with studs for engaging side fixing holes in the drive units. The positioning of the studs is such that the volumes occupied by the mounted units overlap to a large extent. The side members are joined by a flexible member that allows the side members to be flexed out of a normal oppositely-facing configuration for engagement about either of the drive units.

Abstract: A fixing piece is provided for use in fixing a data-storage drive unit and similar units in position on a support structure. The fixing piece is of one-piece plastics form with predetermined fold lines about which the fixing piece can be folded to at least partially encompass the unit. The fixing piece is formed with projections for engaging in holes in the walls of the unit to restrain movement of the latter, and snap-engagable elements for snap engaging in apertures in the support structure to attach the fixing piece, and thereby a unit about which it is folded, to the support structure. A stackable form of this fixing piece is also provided.

Abstract: A locking element fixes a removable connector to a complementary fixed connector provided in a wall. The locking element is provided with first locking means engageable by sliding in a predetermined direction perpendicular to the axis of the removable connector and the fixed connector, with complementary locking means of the removable connector. The locking element is provided with second locking means engageable by sliding in the predetermined direction, with complementary locking means of the wall.