Hier ist Dein Wadler.
MfG
Code:
          HEX H3,H2,H1,H0 --> BCD C,D3,D2,D1,D0    H3,D3 = MSB

                                                   C = Carry
          H H H H
          3 2 1 0

          | | | |
          | | | +----------------------------------------> D0
          | | o--------------------------+ IC1
          | o--------------------+       |  __
          | | |VCC __            |       +-|=1|
          | | | +-|=1|           |         |  |----------> D1
          | | |   |  |-+   IC2   |  __   +-|__|
          o-------|__| |    __   +-|  |  |
          | | |   IC1  +---|>=|  +-|& |------------------> D2
          | | |            |1 |--|-|__|  |
          | | o------------|__|    IC3   |
          o-------------+                |
          | | |VCC __   |   __           |
          | | | +-|=1|  +--|  |          |
          | | |   |  |-----|& |--------------------------> D3
          | o-----|__|  +--|__|          |
          | | |VCC __   |  IC3           |
          | | | +-|=1|  |                |
          | | |   |  |--+                |
          | | o---|__|IC1                |
          | | |    __                    |
          | | +---|>=|      __           |
          | |     |1 |-----|  |          |
          | +-----|__|   +-|& |----------+---------------> C
          +--------------|-|__|
                  IC2      IC3

         IC1=74xx86, IC2=74xx32, IC3=74xx11