as illustrated in fig1 - 3 , a support 10 for a computer or data entry keyboard 12 ( fig4 ) comprises a rectangular frame 14 defining a rectangular opening 16 . frame 14 has a pair of elongate structural members 16 and 18 which form opposite sides of opening 16 . structural members 16 and 18 are disposed in a plane p . a main platform member 20 is pivotably mounted along one side of frame 14 and particularly to structural member 16 , while an auxiliary platform member 22 is pivotably mounted along the opposite side to frame 14 , to structural member 18 . fig1 and 2 show the keyboard support in a closed configuration in which platform members 20 and 22 are disposed in opening 16 and are aligned with frame 14 in plane p . in this configuration , platform members 20 and 22 overlap and are substantially coextensive and parallel with one another in opening 16 . upper or main platform member 20 is connected to structural member 16 via one or more hinges 24 , while lower or auxiliary platform member is secured to structural member 18 via one or more hinges 26 . hinges 24 and 26 may be spring loaded for biasing platform members 20 and 22 upwardly into the closed configuration of fig1 and 2 . as illustrated in fig3 platform members 20 and 22 may be swung out of opening 16 and away from plane p to form a folded - out use configuration . auxiliary platform member 22 is provided at a free end , opposite structural member 18 and hinges 26 , with a plurality of elongate grooves 28 , 30 and 32 for alternately receiving a free end 34 of platform member 20 . platform member 20 is oriented at an angle α relative to plane p , the magnitude of that angle varying depending on whether free end 34 of the main platform member is inserted into groove 28 , 30 or 32 of auxiliary platform member 22 . an upper surface of auxiliary platform member 22 , facing main platform member 20 , is provided with a mirror 36 for facilitating a visual monitoring of keyboard 12 during use ( see fig4 ). an upper surface of main platform member 20 is provided with one or more arrests 38 ( fig3 ) for retaining keyboard 12 on the main platform member , in opposition to a force exerted by gravity , when platform members 20 and 22 are pivoted in a common direction ( generally downwardly ) out of opening 16 and away from plane p . arrests 38 are pivotably connected to main platform member 20 , so that the arrests may be swung into alignment with the main platform member when not in use . one or more recesses 40 may be provided in main platform member 20 for receiving respective arrests 38 . in using the keyboard support 10 , a computer operator co ( fig4 ) pivots platform members 20 and 22 downwardly out of opening 16 and away from plane p . free end 34 of main platform member 20 is inserted into a selected groove 28 , 30 or 32 in auxiliary platform member 22 . the orientation angle α ( fig3 ) of main platform member 20 may be adjusted according to the needs of the individual operator co by shifting free end 34 of platform member 20 from one groove 28 , 30 or 32 to another . arrest or arrests 38 are pivoted out of respective recesses 40 . subsequently , keyboard 12 is placed on main platform member 20 in contact with arrests 38 . while keyboard 12 is disposed at angle α relative to plane p , the operator co views the keyboard via mirror 36 and pushes keys or pad area 42 on keyboard 12 . in order to facilitate the perception of alphanumeric characters and other typographical symbols on keyboard 12 , a keyboard cover 44 ( fig5 ) is provided . cover 44 has mirror images 46 of keyboard characters and symbols . operator co disposes cover 44 over keyboard 12 on main platform member 20 and subsequently views keyboard 12 and cover 44 in mirror 36 , as indicted by a sight line 48 . the images of the reversed character and symbol images 46 in mirror 36 are themselves reversed and therefore perceptible as normally oriented alphanumeric characters and typographical symbols . in order to ensure a secure connection of main platform member 20 and auxiliary platform member 22 in the folded - out use configuration ( fig3 ), i . e ., to releasably connect main platform member 20 and auxiliary platform member 22 to one another when both platform members are pivoted out of opening 16 away from plane p , a connector or cooperating connector elements are provided . these connector elements may take any of a number of equivalent forms , several of which are illustrated in fig6 - 10 . as illustrated in fig6 a hook 50 pivotably mounted to one platform member 20 engages a pin 51 projecting laterally from the other platform member 22 to hold the ends of the platform members together during use of the keyboard support 10 . as depicted in fig7 a ball snap - lock element 54 attached via a flexible web 56 to one platform member 20 cooperates with a socket element 58 attached to the other platform member 22 to maintain the ends of the platform members together during use of the keyboard support 10 . fig8 shows a hook element 60 on a strap 62 joined to one platform member 20 . hook element 60 has a multitude of tiny polymeric hooks 64 which seize a loop element 66 attached to the other platform member 22 , thereby locking the platform members 20 and 22 to one another . hook element 60 and loop element 66 are commonly known as velcro ™. another pair of cooperating connecting elements , namely , a spring loaded sliding pin 68 and a locking pin 70 , are illustrated in fig9 . sliding pin 68 is reciprocatably mounted to one platform member 20 and is provided with an aperture ( not shown ) traversed by the locking pin 70 . sliding pin 68 is provided with a knob or handle 72 , whereby operator co shifts the sliding pin out of platform member 20 , in opposition to a spring force tending to return the pin to platform member 20 . sliding pin 68 is shifted through a hold ( not illustrated ) in platform member 22 , at the bottom of a groove 28 , 30 , 32 . as shown in fig1 , another sliding pin 74 with an actuator knob 76 is locked in an extended position by a c clamp 78 including a set screw 80 . the connecting elements of fig6 - 10 are not necessary in cases where hinges 24 and 26 are provided with strong restoring springs . support 10 can be used as a desk - top type surface , holding a keyboard in a substantially horizontal plane . when operator co desires to use the support for varying the angle α of keyboard 12 relative to horizontal plane p , mirror 36 facilitates viewing of the keyboard . although the invention has been described in terms of particular embodiments and applications one of ordinary skill in the art , in light of this teaching , can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention . for example , frame 14 may have a shape other than rectangular . more specifically , frame 14 may be incorporated in a piece of furniture such as a desk . accordingly , it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof .