-- >
>                        Vcc
>   SW3                   |
>      __I__              R1
>                  +      |                           |
>  +---o   o---o----D3----o--------o----------o-------| B0
>  |           |                   |          |       |
>  R3          |             SW1 | o    SW2 | o       |
>  |           |                -|         -|         |
> Gnd          |                 | o        | o       |
>              |                   |          |       |
>              |         Vcc       |+         |       |
>              |          |        D1         D2      |
>              |          R2       |          |+      |
>              |   +      |        |          |       |
>              +----D4----o--------o----------o-------| B1
>                                                     |




this schematic doesn't make any sence to me.
b0 and b1 are pulled high. when you push sw1 still bo and b1 is high.
same thing with sw2.the only thing will work is sw3.


here this is what I think.        +5
                                  |
                              sw1 R   |
                gnd___________/___|___|B0
                 sw3              |   |
        gnd_______/___+D__________|   |
               |______+D__________    |
                                  |   |
                             sw2  |   |
                gnd___________/___|___|B1
                                  |   |
                                  R   |
                                  |   |
                                  +5  |

Andre  Abelian










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